1 - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
2 - INAF - Istituto di Radioastronomia-Sezione Firenze, Largo E. Fermi 5, 50125 Firenze, Italy

Abstract
Aims. Combining the relative vicinity of the Local Group spiral galaxy M 33 with the Spitzer images, we investigate the properties of infrared (IR) emission sites and assess the reliability of the IR emission as a star formation tracer.
Methods. The mid- and far-IR emission of M 33 was obtained from IRAC and MIPS images from the Spitzer archive. We compared the photometric results for several samples of three known types of discrete sources (H II regions, supernovae remnants and planetary nebulae) with theoretical diagnostic diagrams, and derived the spectral energy distribution (from 3.6 to 24 $\mu$ m) of each type of object. Moreover, we generated a catalogue of 24 $\mu$ m sources and inferred their nature from the observed and theoretical colours of the known type sources. We estimated the star formation rate in M 33 both globally and locally, from the IR emission and from the H ${\alpha }$ emission line.
Results. The colours of the typical IR emissions of H II regions, supernovae remnants and planetary nebulae are continuous among the different samples, with overlapping regions in the diagnostic diagrams. The comparison between the model results and the colours of H II regions indicates a dusty envelope at relatively high temperatures $\sim$ 600 K, and moderate extinction A_V $\la$ 10. The 24 $\mu$ m sources IR colours follow the regions observationally defined by the three classes of known objects but the majority of them represent H II regions. The derived total IR luminosity function is in fact very similar to the H II luminosity function observed in the Milky Way and in other late type spirals. Even though our completeness limit is 5 $\times$ 10³⁷ erg s^-1, in low density regions we are able to detect sources five times fainter than this, corresponding to the faintest possible H II region. The 8 and 24 $\mu$ m luminosities within the central 5 kpc of M 33 are comparable and of order 4 $\times$ 10²⁸ erg s^-1 Hz^-1 ( $\nu L_\nu(8) = 1.5$ $\times$ 10⁴² and $\nu L_\nu(24) = 4.4$ $\times$ 10⁴¹ erg s^-1). We estimate the total IR emission in the same region of M 33 to be 10 $^9~L_\odot$ . The discrete sources account for about one third of the 24 $\mu$ m emission while the rest is diffuse. From the IR emission, we derive a star formation rate for the inner disk equal to 0.2 $M_\odot$ yr^-1, consistent with the star formation rate obtained from the H ${\alpha }$ emission.

Key words: galaxies: individual: M 33 - galaxies: ISM - galaxies: Local Group - galaxies: spiral

The interstellar medium (ISM) in galaxies provides the raw material from which stars form, and is the repository of the products of stellar evolution. Stars form in condensations of cool molecular gas, eventually destroying their birth sites through energetic photons, massive stellar winds, and supernova (SN) explosions. Dust is formed through coagulation in stellar winds and supernova ejecta, and over time, becomes an integral part of the ISM. Radiative and mechanical energy are input to the ISM through massive star formation and evolution, in the form of ionising photons, supernova explosions, and magnetic fields. The ISM properties, such as magnetic field, gas, and dust, affect star formation processes on all scales. At the same time, star formation drives the evolution of the ISM. On the long term, local processes of star formation can influence large-scale structure in the ISM and determine how galaxies evolve. Ultraviolet and optical wavelengths are not the best wavelengths for SF studies, because dust can hide massive star formation, mask the effects of feedback, and redistribute the ISM energy and radiation. However, first IRAS (Neugebauer et al. 1984), then ISO (Kessler et al. 1996), and now Spitzer (Werner et al. 2004) have been able to penetrate the dust in the ISM, and thus better study the interaction among its constituents.

In this series of papers, we examine star formation properties of the Local Group late type spiral M 33. The proximity of Local Group members together with Spitzer resolution makes possible the resolution of structures on spatial scales of 5-10 pc, and enable us to effectively study individual star forming sites and their surrounding environment in a galaxy different from our own. M 33, is at a distance of 840 kpc (Freedman et al. 1991), its mass and apparent size are smaller than that of M 31 but M 33 hosts the brightest H II complex in the Local Group. This, together with its blue colour assures us that star formation is still very active throughout its disk. M 33 bears no signs of recent mergers and therefore gives us a unique opportunity for investigating the interplay of gas, dust, and star formation in isolated galaxy disks. This is possible thanks also to high resolution and sensitive observations now becoming available for this nearby galaxy at all wavelengths. Chemical abundances have been measured in stellar populations of different ages (e.g. Magrini et al. 2007a,b), and surveys of atomic and molecular hydrogen point out the location of massive gas clumps (Heyer et al. 2004; Engargiola et al. 2003). Through detailed dynamical mass modeling of the galaxy we can now trace the mass distribution of visible and dark matter (Corbelli 2003; Corbelli & Salucci 2000).

Our focus here is first on M 33's population of discrete known type of point sources: H II regions, supernova remnants (SNRs), and planetary nebulae (PNe). In principle, these sources track different phases of the star formation process, from the generation of ionising photons and stellar winds in massive stars, to subsequent explosion as SNe and finally to the more evolved stage of PNe. Hence, our immediate goal is to assess the physical conditions of the stellar environment at different stages. The second purpose of this paper is the generation of an IR source catalogue from the Spitzer MIPS observations at 24 $\mu$ m. Here we shall use IRAC-MIPS diagnostic diagrams of known sources to better understand the nature of these sources. In a subsequent paper we will relate the IR properties with detailed observations of the surrounding ISM at other wavelengths and to the disk large-scale structure. Spitzer data and the vast multi-wavelength dataset available for M 33 will help understand how star formation proceeds in low luminosity spiral galaxies and how this relates to other global galaxy properties.

The present paper is structured as follows: in Sect. 2, we present the Spitzer IRAC and MIPS data and their reduction process. The large scale structure of the dust emission in M 33 is investigated through colour images in Sect. 3. We analyse the IRAC and MIPS 24 photometry of discrete type-known sources (H II regions, PNe, SNRs) in Sect. 4 and compare their colours to theoretical diagnostic diagrams in Sect. 5. In Sect. 6, we present a catalogue of the sources emitting in the 24 $\mu$ m MIPS band and interpret their nature in light of the results obtained in the previous Section. The reliability of the IR emission as a star formation tracer, through comparison with H ${\alpha }$ , is investigated in Sect. 7. Finally, the summary and conclusions of our study are given in Sect. 8.

2 Observations and data reduction

We retrieved images from the Guaranteed Time Observations (PID 5, PI R. Gehrz) in the Spitzer Space Telescope (Werner et al. 2004) data archive. The Spitzer Space Telescope carries two photometric cameras: the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPS).

2.1 IRAC data

The Infrared Array Camera (Fazio et al. 2004) is equipped with two detector arrays of 256 $\times$ 256 pixels. The field of view of a single array is $5\hbox{$.\mkern-4mu^\prime$ }2$ $\times$ $5\hbox{$.\mkern-4mu^\prime$ }2$ . We analyze here eight sets of IRAC observations of M 33 (AORs 3636224, 3636480, 3637760, 3638016, 3638784, 3639040, 3640320, 3640576) in all four IRAC bands. The Basic Calibrated Data (BCD) were created by the Spitzer Science Center (SSC) pipeline, version S14.0.0 for all AORs. As the first data frame of each observation sequence has a shorter integration time than the regular exposure time (10.4 s), we discarded those frames. A more complete description of the observations is given by Hinz et al. (2004), McQuinn et al. (2007), and Tabatabaei et al. (2007a).

The mosaics were assembled gathering all the BCDs for each wavelength. The individual calibrated frames were processed using Mopex (Makovoz & Khan 2005), with a cosmic-ray rejection and a background matching applied between overlapping fields of view. During the reduction, we used a common value of the pixel size equal to $1\hbox{$.\!\!^{\prime\prime}$ }20$ . The final number of individual BCDs used is about 1700, in each IRAC channel. The final dimension of the mosaics is approximately $62\hbox{$.\mkern-4mu^\prime$ }4$ $\times$ $91\hbox{$.\mkern-4mu^\prime$ }7$ . Because of the overlap between adjacent BCDs, the mean redundancy is 12 (from 6 to 30).

The obtained IRAC mosaics were background subtracted, estimating 20 sky levels (the median values in 5 $\times$ 5 pixels boxes) near the edges of the mosaics, the farthest from the galaxy centre. The 5.8 and 8.0 $\mu$ m channels presented a gradient in the background, and we removed it using a fitted surface with the IRAF task imsurfit (images.imfit). In each channel, the final background value subtracted is the mean of the 20 median values: 0.059 at 3.6 $\mu$ m, 0.146 at 4.5 $\mu$ m, 1.475 at 5.8 $\mu$ m, and 5.389 at 8.0 $\mu$ m. The mosaics were then aligned using the IRAF tasks geomap and geotran (in immatch) using 15 point sources.

Because of the diffraction limit of the telescope, the images have a resolution of 1 $.\!\!^{\prime\prime}$ 7 to 2 $.\!\!^{\prime\prime}$ 0 (see IRAC Observing Manual) which translate into 6.7 to 8 pc at the distance of M 33. The final IRAC mosaics at 3.6, 4.5, 5.8, and 8.0 $\mu$ m are shown in Fig. 1.

2.2 MIPS data

Images of M 33 at wavelengths 24, 70, and 160 $\mu$ m (with bandwidths of 5, 19, and 35 $\mu$ m, respectively) were obtained using data collected by the Multiband Imaging Photometer (Rieke et al. 2004). MIPS uses true detector arrays: 128 $\times$ 128 pixels at 24 $\mu$ m (Si:As detector), 32 $\times$ 32 pixels at 70 $\mu$ m (Ge:Ga device) and 2 $\times$ 20 pixels at 160 $\mu$ m (Ge:Ga device). The nominal fields of view are 5' $\times$ 5' at 24 and 70 $\mu$ m and $0\hbox{$.\mkern-4mu^\prime$ }75$ $\times$ 5' at 160 $\mu$ m. The resolution of the instrument is diffraction limited to 6'', 18'', and 40'' at 24, 70, and 160 $\mu$ m, respectively. The operating modes of all the observations were "scan map'', the telescope scanning the sky at a constant rate.

As for IRAC, we retrieved eight MIPS datasets from the archive (AORs 3647744, 3648000, 3648256, 3648512, 3648768, 3649024, 3649280 and 3649536). The 24 $\mu$ m BCDs were created by the SSC pipeline version S16.1.0. The exposure times of the DCEs were 3.67 s (except for the first frames of each series, where the integration time per pixel is lower and which consequently were not used in the further reduction steps). Since the observations were acquired over two epochs, the respective mosaics were assembled separately using Mopex. For consistence with the IRAC reduction, the pixel size was chosen to be 1 $.\!\!^{\prime\prime}$ 20. The first epoch includes 4199 frames, and the second one includes 4500 frames. This latter map is displayed in Fig. 2. The mean redundancy per sky position is 22 (varying from 10 to 40), in each mosaic. This high level of redundancy removes any spurious effects such as cosmic-ray hits and provides more reliable measurements. In the present article, as we plan to focus on point sources (H II regions, SNRs and PNe) located near the centre of the galaxy, we chose to concentrate, for each epoch, on the two central AORs. These two images were then aligned with the reference of the coordinates of 8 point sources and combined together by keeping the average of the pixel values. A small background gradient was still visible in the combined image and was removed by fitting a surface to selected regions (IRAF task: imsurfit). The zone defined by the superposition of the two central AORs of each epoch is marked on the 24 $\mu$ m image (see Fig. 2). The resolution measured on the final image is 6''.

The 70 and 160 $\mu$ m MIPS observations were acquired with the same AORs as the 24 $\mu$ m observations. The version S16.1.0 of the SSC pipeline was also used to create the BCDs. The integration times of the DCEs is 4.19 s, both for the 70 and 160 $\mu$ m observations. We used Mopex to create the final mosaics (again the pixel sizes were chosen to be $1\hbox{$.\!\!^{\prime\prime}$ }2$ ), including 8750 individual frames at each of the two wavelength channels. The mean redundancy is about 20 (from 8 to 42) and 6 (from 2 to 10) at 70 and 160 $\mu$ m, respectively. The final images show some striping along the scan direction that is a residual instrumental artifacts due to the time-dependent responsivity of the Ge:Ga detectors (Helou et al. 2004; Hinz et al. 2004). The final resolution is about 16'' and 40'' for the 70 and 160 $\mu$ m images, respectively. The final MIPS images (24, 70, and 160 $\mu$ m) are shown in Fig. 2.

2.3 H ${\alpha }$ image

We also include in our analysis an optical narrow-band H ${\alpha }$ image, a standard star formation indicator. The M 33 H ${\alpha }$ emission was observed at the Kitt Peak National Observatory (NOAO). The dimensions of the CCD are 2048 $\times$ 2048 with pixels of $2\hbox{$.\!\!^{\prime\prime}$ }03$ and a total field of view of about 70' $\times$ 70'. More details of the observations and reduction process can be found in Hoopes & Walterbos (2000); the estimated [N II] contamination accounts for at most 5% of the measured flux. The total H ${\alpha }$ luminosity of M 33 is about 7 $\times$ $10^6~L_\odot$ and is dominated by H II regions (Devereux et al. 1997). The optical extinction in M 33 is found to be globally low, A_V < 0.4 mag. Towards H II regions A_V $\sim$ 1 mag on average even though it can reach values as high as 2 mag towards high surface brightness cores (e.g. Israel & Kennicutt 1980; Devereux et al. 1997). The moderate values of extinction imply that H ${\alpha }$ can be used as an SF tracer globally, but towards individual sources an extinction correction can become necessary.

3 Large scale structure of stars and dust

In the present paper, we concentrate on the inner region of M 33 as defined by the Spitzer inner AORs which is outlined by the continuous line in Figs. 1 and 2 for the IRAC and MIPS data, respectively.

In order to help the interpretation of Spitzer data, we first review briefly which are the main emission phenomena that dominate each IRAC and MIPS waveband.

3.1 Origin of the emission detected by Spitzer

The stars (mainly Red Giant Branch and/or Asymptotic Giant Branch, according to the age of the population) account for most of the emission in the 3.6 $\mu$ m IRAC band. A mix of stars and very hot dust continuum contribute to the emission in the 4.5 $\mu$ m band. Nevertheless, in discrete sources with negligible continuum (see Sect. 4), the emission seen in both these bands can have a strong component of ionic and molecular lines (e.g., Reach et al. 2006; Williams et al. 2006). In the 5.8 $\mu$ m IRAC band, the stellar contribution decreases and the dust continuum component gets stronger. The longest-wavelength 8.0 $\mu$ m IRAC band still traces hot dust continuum but in most cases, the polycyclic aromatic hydrocarbons (PAH) dominates. If there are no PAHs and low continuum, however, in discrete sources there can be a sizable contribution from two H₂ lines and the [Ar III] at 8.9 $\mu$ m (e.g., Hora et al. 2004).

The PAH emission features (mainly concentrated at 3.3, 6.2, 7.7, 8.6, and 11.3 $\mu$ m) are the optically active vibrational modes of PAH molecules (Leger & Puget 1984; Allamandola et al. 1989), resulting from internal conversions of energy following absorption of an optical or UV photon. The IRAC bands 3.6, 5.8, and 8.0 $\mu$ m contain PAH emission features at 3.3, 6.2, and 7.7 & 8.6 $\mu$ m, respectively (Churchwell et al. 2004; Draine 2003). The 4.5 $\mu$ m channel is the only one with no PAH features, although it contains the bright hydrogen recombination line Br ${\alpha }$ (4.05 $\mu$ m).

We investigate the far-infrared (FIR) emission with the MIPS images. The 24 $\mu$ m emission is contributed partly by thermal emission of classic (large) dust grains and partly by very small grains (VSGs). Indeed, VSGs were introduced by Desert et al. (1990) as the carrier of the emission in the 25 $\mu$ m IRAS band. The 70 $\mu$ m emission traces cooler dust, and the 160 $\mu$ m one shows the diffuse cold dust component.

3.2 Structure of infrared emission in M 33

Figure 1 shows that the stellar component is smoothly distributed everywhere in the disk of M 33. The warm and hot dust traced by the 5.8 $\mu$ m channel smoothly follow the morphological patterns (spiral arms and flocculent structures) of M 33 with a higher concentration in the inner part of the galaxy. Compared with the other components, the 8.0 $\mu$ m contribution shows most clumpy distribution; evidently PAHs are preferentially located along the spiral arms and flocculent structures, rather than being uniformly distributed in the ISM. The very centre of the galaxy gathers all the three contributions: stars, dust and PAHs.

3.3 The colour images

To help investigate the large scale structure of M 33 as seen by Spitzer we made two sets of colour images: one degraded to the worst resolution of the IRAC channels, and a second set degraded to the resolution of the MIPS 24 $\mu$ m image. We approximated the PRF with a Gaussian and convolved both sets to the resolution of the worst image in the set (8 $\mu$ m and 24 $\mu$ m, respectively).

Figure 3 shows the 3.6/4.5 ratio (left panel) and 4.5/8.0 ratio (right) of M 33. The 3.6/4.5 shows a remarkably constant ratio ( $\sim$ 1.7) over almost the entire galaxy, confirming the statement by Pahre et al. (2004), who find that for each galaxy, the [3.6]-[4.5] colour is nearly constant with radius and consistent with stellar photospheric emission. The 5.8/8.0 ratio (not shown in Fig. 3) is also approximately constant ( $\sim$ 0.5), similarly to other galaxies such as NGC 300 by Helou et al. (2004), even though it might not be a general feature. In both the 5.8 and 8.0 $\mu$ m bands there is an increase of the diffuse emission relative to the 3.6 and 4.5 $\mu$ m bands, as in our Galactic plane. The 8.0/24 colour (not shown) also does not show any evident radial gradient or prominent structure and is practically constant across the disk. Similarly to the 5.8/8.0 ratio, this result points out the overall constancy in the ratio of PAHs and warm dust emission in this galaxy.

On the other hand, the 4.5/8.0 images (right panel of Fig. 3) and the 3.6/5.8 ratio (not shown) both retain the structural pattern of M 33, tracing the inner features, the two main spiral arms and the filamentary structure of the disk. In the first case, this is probably due to the predominant PAH features in the spiral arms and filaments; in the second, the ISM as reflected in the 5.8 $\mu$ m band is emerging relative to the stars at 3.6 $\mu$ m. The 8.0 $\mu$ m emission along the spiral arms and along filaments surrounding the dimmer star forming regions at large galactocentric distances become prominent.

We also constructed an IRAC three colour image of M 33 by subtracting the stellar component in the shorter-wavelength images from the 5.8 and 8.0 $\mu$ m ones. To remove the stellar contribution from the 5.8 and 8.0 $\mu$ m images, we used the recipe by Helou et al. (2004); Perez-Gonzalez et al. (2006); Calzetti et al. (2005); Pahre et al. (2004). The 3.6 and 4.5 $\mu$ m images were combined assuming colours appropriate for an M0 III star ([3.6]-[4.5] = -0.15 in Vega mag). The final combination is shown in Fig. 4 and displays the stars in blue, the star-subtracted 5.8 $\mu$ m in green and the star-subtracted 8.0 $\mu$ m in red. The dominance of the 8 $\mu$ m emission in the spiral arms is clearly revealed by Fig. 4. The underlying stellar disk is also evident; the excess of stellar light in the centre has been pointed out by previous near-infrared ground observations (Regan & Vogel 1994), and is related to the possible presence of a bulge or bar component.

3.4 Distribution of cool dust

Over the last fifteen years, many studies have been devoted to the FIR emission of M 33 using IRAS and ISO. Rice et al. (1990) observed M 33 with IRAS at 12, 25, 60, 100 $\mu$ m and found a striking correlation between the spatial IR structure and the H II regions. They estimated that 75% of the integrated IR emission arises from stars younger than a few times 10⁸ yr. The close correspondence between the H ${\alpha }$ image and the FIR (60 and 100 $\mu$ m) morphology was also noted by Devereux et al. (1997). Hippelein et al. (2003) studied M 33 with ISOPHOT at 60, 100 and 170 $\mu$ m, and concluded that the FIR emission is composed of a superposition of two components: i) a warm one, found in spiral arms and SF regions, heated by UV radiation from OB stars, contributed by dust at about 45 K; and ii) a cold one around 16 K which is smoothly distributed over the disk and heated by diffuse interstellar radiation.

More recently, Hinz et al. (2004) used MIPS observations of M 33 to investigate the origin of the FIR emission, and found that the emission in the 24 and 70 $\mu$ m MIPS images follows closely the structure of the ionised gas, suggesting heating by hot, ionising stars. The overlays of Fig. 6 (see Sect. 3.5) show the link between 24 and H ${\alpha }$ , i.e. between the hot dust emission and the formation sites of massive stars (see also Tabatabaei et al. 2007a). This link is also evident by comparing the H ${\alpha }$ and 70 $\mu$ m emission maps. Moreover, comparing thermal and non-thermal radio images of M 33 with MIPS suggests that the 24 and 70 $\mu$ m emission is more closely associated with the thermal radio component than with the non-thermal one (Tabatabaei et al. 2007a). Both the 24 and the 70 $\mu$ m emission originates in fact from warm dust associated with massive star formation. We discuss in more detail the connection between 24 $\mu$ m discrete sources and H ${\alpha }$ knots below.

A more diffuse component emission at 160 $\mu$ m is evident when comparing it with the 24 $\mu$ m map. Cold dust heated by a diffuse interstellar radiation field clearly contributes to the longer wavelength MIPS band.

3.5 Comparison with H ${\alpha }$

In Figs. 5 and 6, we show the 8.0 and 24 $\mu$ m contours on the H ${\alpha }$ image. Other than the two brightest H II regions (NGC 604 and IC 133), the highest levels of 24 $\mu$ m emission are concentrated in the inner part of the galaxy, and the 24 $\mu$ m emission mainly follows the spiral arms. Notably, not all the H ${\alpha }$ bright spots have bright 24 $\mu$ m counterparts. Moreover, the centre of the 24 $\mu$ m emitting sites can be shifted with respect to the centre of the H ${\alpha }$ emission sites. This might indicate that some of the optical emission from the H II regions is obscured by dust or may be due to different intrinsic structures related to the evolution of H II regions. Of particular interest are the 24 $\mu$ m emission spots not associated with H ${\alpha }$ emission, which could trace deeply embedded H II regions, or a different population of objects. In Fig. 5, we can see the same general trends with a concentration of the 8 $\mu$ m emission in the centre and along the spiral arms of the galaxy. At larger radii, the 8 $\mu$ m emission becomes more diffuse respect to the 24 $\mu$ m component which matches better the bright H ${\alpha }$ knots. At 8 $\mu$ m, the southern arm shows a much more concentrated emission than the northern arm. A similar trend has also been found for the molecular gas: giant molecular clouds and diffuse molecular gas emission follow the pattern of the arm in the south as traced by H ${\alpha }$ much more closely than in the north (Heyer et al. 2004; Engargiola et al. 2003).

4 The IR emission of nebulae in M 33

We used six catalogues of three classes of known-type sources in M 33: three catalogues of H II regions selected at different wavelengths, two catalogues of SNRs, and one catalogue of PNe:

We have selected our sample of H II regions from three different catalogues, which include H II regions of different morphologies, locations within the galaxy, and brightness. Our IR sample was obtained by merging the sources observed by Willner & Nelson-Patel (2002) and Giveon et al. (2002). It includes in total 28 sources located in three chains, to the east, west, and south of the galaxy nucleus. Our radio sample comprises 40 H II regions with 20-6 cm spectral index ( $\nu^\alpha$ ) ${\alpha }$ > -0.2 as catalogued by Gordon et al. (1999), and extends out to 20' galactocentric radii. A list of 78 optically selected H II regions, from narrow band images and with known optical spectra, was kindly provided to us by L. Magrini (Magrini et al. 2007b). Such regions are in general much fainter than the IR or radio selected regions and are located preferentially at large galactocentric radii.

To probe dust emission during the final stages of stellar evolution, we selected two samples of SNRs, one defined optically and one defined in the radio. The optical sample (Gordon et al. 1998) contains 98 SNR candidates selected primarily on the basis of optical emission-line ratios. The radio sample of SNRs contains 30 (radio-bright) sources appearing both in Duric et al. (1995) and Gordon et al. (1999). Their selection criteria are effective at finding middle-aged remnants. In fact, since their SNRs have diameters in the range 20-48 pc, most of the SNRs should be in the Sedov-Taylor expansion stage. The contamination in their sample is estimated to be less than 1, but there are 20 SNRs embedded within H II regions. Still, several remnants are associated with nearby H II regions and some are embedded in them.

Finally, we adopt the catalogued PNe of Ciardullo et al. (2004). As a result of a photometric and spectroscopic survey, they identified 152 PNe candidates in M 33. By comparison with Magrini et al. (2001), the contamination by H II regions or SNRs is estimated at $\sim$ 22%.

4.1 Photometric methodology

We have six source lists of known type, for a total of more than 400 objects distributed over the entire disk of M 33. Our aim is to use the IRAC/MIPS-24 colours of these as empirical diagnostics to infer the dust properties in various kinds of nebulae. This is done by comparing their IR colours with the theoretical colour diagrams (see Sect. 5).

To these source lists we then add the 24- $\mu$ m selected sample and we shall infer the nature of these sources by comparing their IR colours with those of known-type of sources (see Sect. 6). We are also interested in the H ${\alpha }$ emission of our objects, in particular for the 24- $\mu$ m selected sample and therefore we need to perform photometry on the H ${\alpha }$ image. Therefore, we must perform photometry in a total of six bands (4 IRAC, MIPS-24, and H ${\alpha }$ ). We merge the IR photometry, and consider only those sources which have measurable emission in all the IR bands examined, in order to place them on our diagnostic colour diagrams.

The proximity of M 33 combined with the superb resolution of Spitzer makes photometry of individual sources in the galaxy challenging. Isolating sources is difficult, because of the extremely crowded fields, especially the inner disk and circumnuclear regions. Moreover, we expect that many of the objects (e.g., H II regions and SNRs) will be extended, so that we cannot accurately perform point-source fitting and subtraction with point-response functions. In addition, many classes of sources are not prodigious emitters in the mid-infrared (MIR), which further complicates the automatization of the photometric procedures. Hence, we investigated many photometric schemes before finally arriving at a reliable solution.

Following Calzetti et al. (2005), we first attempted aperture photometry of the sources in our lists. The initial centres were taken from the source lists described in Sect. 4, and the centre of the virtual aperture was then allowed to vary up to a certain distance from the initial position. While this is a viable solution in other situations, it turned out not to be feasible in M 33. First, the definition of the fiducial aperture should depend on source extent, but this differs among the source classes, so it was not clear how to define the limiting aperture. This was an especially vexing problem for the wavelengths in which a given source does not have measurable emission, since the automatic centring routines did not converge. Second, the determination of the background was extremely problematic because of the variable degree of crowding and the variable degree of diffuse emission. It was also unclear how to define either "regional'' or "global'' backgrounds in the case of M 33. Thus, we were forced to find another solution.

We then attempted elliptical cross-section Gaussian fitting of sources (e.g., Calzetti et al. 1995). The fitting box was fixed to a series of dimensions (from 25 to 10 pixels), and the centre, the orientation, the width, and a constant background level were left free to vary. As before, the initial centres were taken from the source lists. The larger fitting boxes allowed the centre to wander too much from the initial position. Hence, the source identified by the fitting routine frequently did not correspond to the source in the list, although reasonably accurate backgrounds were obtained when checked against the source surroundings. The smaller fitting boxes better constrained the centre, but in crowded fields gave a background which was much too high. This resulted in gross underestimations of the total flux, especially when the source was rather faint and comparable to the estimated background. An additional problem encountered with Gaussian fitting was its unsuitability for multiple sources. Many of the sources in our lists are in truth "clusters'' of smaller sources when examined with the Spitzer spatial resolution and at wavelengths different from those in which the sources were defined. These problems taken together led us to distrust this method for a large fraction of sources in our lists.

To overcome these shortcomings, we finally devised a "hybrid'' solution, which optimally combines the photometry from Gaussian fitting and that from isophotal photometry. This last was accomplished with SExtractor (Bertin & Arnouts 1996) which is able to deal with very large images automatically, and handles reasonably accurately a wide variety of object shapes and sizes. The idea was to calculate the total flux integrated over an irregularly shaped aperture containing flux levels above some isophotal limit. The hybrid method consists of three steps: (1) perform Gaussian fitting of all sources as described in the previous paragraph; (2) perform SExtractor photometry as described below; (3) merge the two sets of photometry according to an algorithm which decides which photometric measurement to prefer, in order to have one measurement per source.

For (1), we adopted a fitting box of 10 pixels; this was the best compromise between centre wandering and background level, as the photometry was typically centred on a position relatively close to the initial one, although with a potentially spuriously low flux because of the background determination.

In practice, for (2), we used the ASSOCIATIVE feature of SExtractor, and input our source lists with initial positions. The initial SExtractor photometry consisted in those sources extracted at a 10 $\sigma$ level above the background, at a distance within 15 pixels ( $\equiv$ $\Delta {r}$ ) from the initial position. These two values resulted to be the best compromise between source association and source identification. Lower values of signal-to-noise ratio (< $10\sigma$ ) resulted in more sources being identified, but were in the mean farther away. The background for the SExtractor photometry was defined to be the local median of the image in a 64-pixel box centred on the source.

Step (3), the merging of the Gaussian fitting and SExtractor photometry, was accomplished by examining the radial distance of each measurement from the initial position. When the SExtractor centre was within $\Delta {r}$ of 5 pixels (in radius), and as long as it was within a factor of two of the Gaussian fitting centre, it was preferred over the Gaussian method. We experimented with a few values of $\Delta {r}$ and a few values of the relative ratio of the radial distances, and concluded that this gave the best results overall. Indeed, it appears that this hybrid approach overcomes the problems of underestimating source fluxes because of background estimates, and successfully calculates the total flux even when sources are in fact multiple. Indeed, the SExtractor photometry and the Gaussian fitting results are fairly well correlated except for low fluxes with high background where Gaussian fitting tends to underestimate the true flux, and high fluxes for extended or clustered sources.

4.2 Detection rates

The detection statistics are illustrated in Fig. 7 and Table 1. The matching radius $\Delta {r}$ $_{\rm max}$ for the coincidence of sources, was determined by examining the scatter on the diagnostic diagrams, see Sect. 5. In the end we adopted a value $\Delta {r}$ $_{\rm max}$ = 3 pixels (about 14 pc), which is sufficiently large to accommodate possible astrometric uncertainties.

**Table 1:** Detection rate in all four IRAC and IRAC+MIPS-24 bands.
	IRAC	Total	%	IRAC+MIPS-24	Total	%
ISO	17	27	61%	15	27	54%
Hra	18	38	45%	18	37	45%
H II	27	77	35%	19	60	32%
SNo	3	98	3%	2	92	2%
SNR	1	30	3%	1	28	3%
PNe	9	141	6%	4	118	3%
24Ss	306	515	59%	306	515	59%

The positions of catalogued sources with photometry in all four IRAC bands are shown in Fig. 8, on the IRAC 4.5 $\mu$ m image of M 33. The upper panel refers to H II regions and we note that the optically selected sample is mainly in the outer regions of the galaxy, while the IR and radio selected H II regions are in the inner parts of M 33. The lower panel shows the locations of PNe and SNRs. The single detection of the radio-selected SNR coincides with an optically-selected one.

4.2.1 HII regions

The detection rate of H II regions depends on the waveband and on the catalogue. As expected, the brighter H II regions (radio and IR sample) are detected at a higher rate than the faint ones (optically selected catalogue). The detection rate for bright regions increases even more if we loosen the strict requirement about the centre displacement. For large H II regions in fact the centre of the IR emission can be displaced by more than 3 pixels from the nominal position, and hence not accepted as coincident. The lower resolution in the 24 $\mu$ m band makes objects rounder, and the Gaussian fitting is often more accurate than in the 5.8 and 8.0 $\mu$ m band. This partly accounts for the higher detection rate in the 24 $\mu$ m MIPS wavelength. But, there is a general tendency for the H II regions to be less visible in the shortest wavelengths (3.6 and 4.5 $\mu$ m) than in the 8.0 and 24.0 $\mu$ m channels. The detection rate at 5.8 $\mu$ m always shows a drop, with respect to the adjacent channels (see Fig. 7).

4.2.2 Supernovae remnants

We found a low rate of IR counterparts for the SNRs identified in optical and in radio. The percentage of detections is about 15% for both samples. Four SNRs were detected in at least one band: two were detected at all wavelengths, and other two only at 4.5 $\mu$ m. The four detected SNRs have radii of $\sim$ 8-16 pc, while the two undetected ones have radii greater than 20 pc and may be of a lower surface brightness. The low number of SNR detections is consistent with previous IRAS studies trying to find Galactic SNR counterparts in the IR: 17% (Arendt 1989) and 18% (Saken et al. 1992). Also, using IRAC, Reach et al. (2006) found only 18 IR counterparts out of 95 SNRs in the inner Galaxy. Very few Galactic SNRs were detected by MSX, the Midcourse Space Experiment (Cohen et al. 2006). In the Large Magellanic Cloud, Borkowski et al. (2006) found no emission from type Ia SNRs and Williams et al. (2006) did not detect the two largest SNRs of their sample in any of the IRAC or MIPS wavebands.

In our samples, the detection rate is also about 30% less in the 8.0 and 24 $\mu$ m bands with respect to the shorter IRAC wavelengths. This might be due to the destructive effect of the blast wave on the smaller grains; PAHs can already be razed in slow shocks and they are never detected in dense, shocked clumps (Reach et al. 2002). The emission seen at 3.6 and 4.5 $\mu$ m is likely due to ionic and molecular lines, such as Br ${\alpha }$ 4.1 $\mu$ m (Reach et al. 2006; Williams et al. 2006). The environment of the SNRs should have a strong influence on their IR detection rate: remnants interacting with a denser external medium should be more easily detectable. If PAHs in the surrounding ISM are destroyed by nearby supernova events (Gorjian et al. 2004), they will not emit at 8.0 $\mu$ m (nor contribute to 3.6 and 5.8 $\mu$ m), which could explain the quite low rate of detection of a remnant in all 4 bands.

4.2.3 Planetary nebulae

The detection rate of PNe is about 25% for the three shorter IRAC wavelengths and then rises steeply to reach more than 50% in the 24 $\mu$ m band. This is consistent with the result by Cohen & Barlow (2005) who detect PAH emission in less than half of a sample of 43 Galactic PNe. In addition, Hora et al. (2004) claim that the IRAC colours of PNe are red; despite typically negligible continua, they are bright in the 8.0 $\mu$ m band probably because of a sizable contribution from the two H₂ lines and an [Ar III] line at 8.99 $\mu$ m.

4.3 Spectral energy distributions

The average IR Spectral Energy Distribution (SED) for our different lists of objects is shown in Fig. 9. H II regions, either IR or radio selected, display the highest fluxes, about two order of magnitudes above the faintest in the list, that is the PNe. The H II optical sample instead, largely consisting of quite faint regions, sits at lower values, in between the two samples of SNRs. The steep rise between 8.0 and 24 $\mu$ m of all the H II regions samples, implies that H II regions are invariably associated with warm dust. SNRs and PNe show milder slopes, their SEDs being almost flat, or even declining as for optically selected SNRs. This last feature reveals changes of the ISM characteristics related to SN events.

In H II regions, the drop between 3.6 and 4.5 $\mu$ m can be accounted for by the photospheric contribution of young stars in the two shortest wavelength IRAC channels or perhaps line emission. Candidate lines in the 3.6 $\mu$ m band include [Fe III] 3.229 $\mu$ m, and [Co III] 3.492 $\mu$ m (Gerardy et al. 2007), but line emission can be important in other bands as well as long as there is little continuum emission. This drop has also been detected by Gerardy et al. (2007); Jones et al. (2005); Mercer et al. (2004); Gorjian et al. (2004); Williams et al. (2006). The absence of the 4.5 $\mu$ m drop in the means of radio selected H II's is due primarily to a single object with a high 4.5 $\mu$ m flux.

5 Diagnostic diagrams

5.1 Theoretical diagnostic diagrams for IRAC and IRAC/MIPS flux ratios

To better understand the IRAC/MIPS colour diagrams of discrete sources, we assembled a series of models with different physical parameters, as described more in detail below. The IR colours are derived by convolving the model spectra with the IRAC and MIPS-24 filter response curves, as provided by the Spitzer Science Center web page. The colours are here computed as ratio of flux densities (in Jy, i.e. per unit frequency).

5.1.1 HII regions with Cloudy

H II regions are possibly the most prominent class of sources in our images. We modelled them with version 05.07 of Cloudy, last described by Ferland et al. (1998) (see also Ferland 2003). The central star was taken to be a log g = 4 Kurucz model (Kurucz 1979) at $T_{\rm eff}$ = 37 000 K, as modified by Rubin to better account for the stellar flux in the model atmospheres between 41 eV and 54 eV. In all cases, we assumed a stellar ionising luminosity of 10⁴⁹ s^-1, spherical geometry, constant gas density, a covering factor of 0.005, and a metal abundance of 50% solar.

Grains were "turned on'' in the Cloudy models so that heating and cooling of the grains and the gas are calculated in a self-consistent way. A standard PAH distribution is included in the grain population, with treatment of photoelectric heating and collisional processes (see Ferland et al. 1998). We did not explicitly introduce a photo-dissociation region (PDR) in the calculations.

We accounted for the range in typical H II region parameters by varying the outer radius and the total hydrogen density so as to roughly follow the well-known size-density $n_e \sim D^{-1}$ relation for H II regions (Kim & Koo 2001; Garay & Lizano 1999). Four models were calculated with the following pairs in size-density space with density given first in cm^-3 followed by outer radius in pc: (1000,2); (100,10); (20,30); (10,60).

The resulting spectra are shown in Fig. 10, where the (blue) short-dashed line shows (100,10); the (cyan) dotted line (20,30); the (green) long-dashed line (10,60); and the (red) solid line (1000,2). It can be seen from the figure that varying the density by a factor of 100 drastically changes the PAH emission and its dominance relative to the continuum. Since the PAHs in most H II regions originate in the surrounding PDR rather than in the ionised region itself (e.g Churchwell et al. 2004; Dopita et al. 2006; Whitney et al. 2004), the simulations may not be truly representative of H II regions unless a PDR is absent. However, they clearly span a wide range in IR peak wavelength and PAH strength, so should be adequate for helping to interpret the IRAC/MIPS24 diagnostic diagrams.

5.1.2 Embedded HII regions with DUSTY

The H II regions we have modelled with Cloudy are basically optically thin, because we have not performed multiple iterations on the solution. Moreover, even with iteration, optical depth effects in the dust itself are not taken into account in the Cloudy formalism. Hence, to better model compact and ultra-compact H II regions which are expected to be embedded in an opaque dust cocoon, we have run a series of models with DUSTY (Ivezic & Elitzur 1997). DUSTY solves semi-analytically the radiative transfer physics in a dust envelope by exploiting the self-similar nature of the problem. The dust is located in a shell external to the H II region itself. The program allows for a variety of spherical shell configurations, and provides a realistic spread of dust temperatures as the radiation field changes with distance from the source. At the same time, this code suffers from some limiting assumptions, such as spherical symmetry, no treatment of stochastic processes for PAH emission, and the decoupling of the gas from dust. Nevertheless, for our purposes, it is a powerful tool with which to investigate the dust continuum emission from young dust-enshrouded stars and star clusters.

With DUSTY, it is necessary to specify the temperature at the inner radius of the dust shell, $T_{\rm in}$ which, for a given incident radiation field, determines the inner radius of the region, $R_{\rm in}$ . The radial distribution of the dust is described through the ratio of the outer radius to the inner one, $Y_{\rm out}$ ( $\equiv$ $R_{\rm out}/R_{\rm in}$ ), and the power-law exponent p describing the radial fall-off R^p. In all cases, we adopted a standard "MRN'' size distribution (Mathis et al. 1977), and a standard dust composition (Draine & Lee 1984). Finally, we must specify the radial optical depth A_V which, for a given geometry, fixes the dust mass. The DUSTY models were calculated for 10 values of A_V, ranging logarithmically from 0.1 to 100 (specifically 0.1, 0.215, 0.464 for each decade in A_V). We adopted single-zone models, with only one stratum in the shell.

Two temperatures were input for $T_{\rm in}$ , 300 K and 600 K, which correspond roughly to the range observed in extragalactic H II regions (Hunt et al. 2005). Because of the non-negligible thickness of the dust shell, such relatively high temperatures at its inner rim are also required to explain the average temperatures observed in Galactic H II regions (Giveon et al. 2007; Conti & Crowther 2004). We fixed the power-law exponent p to -0.2 as a compromise between uniform regions and those with a steeper fall-off. This exponent strongly affects the amount of cool dust in the shell, but does not significantly influence the MIR portion of the spectrum that we are examining with the IRAC/MIPS-24 diagnostic diagrams. The thickness ratio $Y_{\rm out}$ varied from 10 to 10 000; $Y_{\rm out}$ also controls the amount of cool dust in the shell as thicker shells have proportionately more cool dust.

To model the exciting star cluster input to DUSTY, we incorporated the Starburst 99 simulations (SB99, Leitherer et al. 1999). Because we are interested in young, dusty star clusters, a single age of 3 Myr was used. SB99 takes into account the nebular continuum emission which can dominate the near-infrared (2 $\mu$ m-4 $\mu$ m, NIR) spectral range, and thus could in principle significantly influence our IRAC colour diagrams (see below). In practice, the slope of the input spectrum of a 3 Myr starburst is quite similar to the star used for the Cloudy simulations, at least down to 0.1 $\mu$ m, so we expect few systematic differences in the dusty star clusters modelled with DUSTY relative to the Cloudy models. The metallicity of the input spectrum was taken to be 20% solar; this was to better account for possible lower-metallicity embedded sources in the outer disk. However, as illustrated below, this choice of metallicity does not significantly affect the resulting IRAC/MIPS-24 colours.

We show examples of the resulting DUSTY spectra in Fig. 11. Here we plot only 5 values of A_V, namely 0.1, 2.15, 10.0, 21.5, and 100 (shown as long-dashed, short-dashed, dotted, dot-dashed, and solid lines, respectively). Also shown (as a heavy solid line which ends at $\lambda \sim 100~\mu$ m) is the input stellar spectrum of a 3 Myr starburst from SB99. The figure clearly shows the importance of nebular continuum emission and the onset of warm dust in the spectral region sampled by IRAC.

5.1.3 Blackbodies

To illustrate the similarity between the emission from stellar populations and blackbodies in the IRAC bands, we also calculated blackbody spectra at temperatures ranging from 100 000 K to 300 K. In the IRAC/MIPS spectral region, there is virtually no difference among the blackbodies from 100 000 K to 3500 K. As expected, their colours are also very similar to the SB99 simulations of the stellar populations in a 3 Myr cluster.

5.1.4 Interstellar medium with PAH features

An example of the spectrum of the diffuse ISM at high Galactic latitudes was also included in the diagnostics. The spectrum was taken from Fig. 8 of Li & Draine (2001), and the digital version was kindly provided by B. Draine. In the IRAC/MIPS-24 spectral range, the diffuse high-Galactic latitude ISM shows extremely strong PAH emission, superimposed on a rising continuum.

5.1.5 Reflection nebula NGC 7023

NGC 7023 is a well-studied PDR that, because of its proximity, is an excellent source to study the physical processes occurring in such regions. It is a reflection nebula illuminated by a B3Ve star, and is located in a cavity of the molecular cloud. This cavity hosts a dense PDR with its peak located away from the star itself (Fuente et al. 2000). We obtained the short-wavelength portion of the ISO spectrum of this object from the uniform database published by Sloan et al. (2003). Like the diffuse ISM, NGC 7023 also shows relatively strong PAH features superimposed on a rising continuum.

5.1.6 Results

The IRAC and IRAC/MIPS-24 diagnostic diagrams relative to the models described above are shown in the bottom panels of Figs. 12-14. Blackbodies are depicted by filled black circles. NGC 7023 is represented by a (yellow) triangle, the diffuse high-latitude ISM by an inverted (cyan) triangle, the SB99 simulations by (grey) diamonds. The Cloudy H II region is represented by filled green squares. Finally, the DUSTY models are represented by filled ( $T_{\rm in}$ = 300 K) and empty ( $T_{\rm in}$ = 600 K) circles, for a variety of shell thickness $Y_{\rm out}$ = 10 (solid), 100 (dashed), 1000 (dash-dot) and 10 000 (dotted line).

There are several interesting features that can be noticed in the plots. First, a PAH-dominated spectrum such as the diffuse ISM, the small dense Cloudy H II region, and the reflection nebula have virtually identical IRAC colours to some of the $T_{\rm in}$ = 300 K DUSTY models. The implication here is that strong PAH features can be easily confused with a rising continuum in the MIR. The only way to resolve the ambiguity is through detailed spectral information or by using the 24 $\mu$ m filter in conjunction with the IRAC 8 $\mu$ m one. Indeed, our plots show that only 2 IRAC filters, together with MIPS-24, are sufficient to separate strong continuum emission in the MIR from strong PAH features. Second, Fig. 12 shows that strongly embedded sources (e.g., A_V $\sim$ 100) occupy a well-defined region in the IRAC colour diagram. This may potentially be useful for singling out ultra-compact dusty H II regions from our 24 $\mu$ m source catalogue. Third, stars (roughly equivalent to 3500 K blackbodies) occupy a well-defined region in both diagrams, and should therefore be easily separable from other classes of objects.

On the negative side, the DUSTY model predictions in the IRAC/MIPS-24 diagram are not easily distinguishable from Cloudy predictions. Moreover, even the highly embedded clusters do not occupy a distinct region in the colour diagrams. This makes the use of IRAC bands necessary, in order to better separate high extinction regions from optically thin ones.

5.2 Observational diagnostic diagrams

A comparison of the IRAC colours of the models+templates vs. observations of the different kinds of nebulae of Sect. 4 is shown in Figs. 12 and 13. Diagnostic diagrams using IRAC colours were presented by Reach et al. (2006) (focusing on SNRs emission mechanisms) and by Cohen et al. (2007). We present two versions of the IRAC diagram, in order to better assess the diagnostic value of the different ratios. We also propose in Fig. 14 a new diagnostic diagram involving the 24 $\mu$ m MIPS channel which allows us to disentangle some degeneracies present when using only IRAC colours. In the next section, will use both the theoretical colour diagnostics and the observed colours of known-type objects to investigate the nature of sources selected at 24 $\mu$ m.

5.2.1 HII regions

In the first IRAC colour diagram (see the middle panels of Figs. 12 and 13), we find a concentration of H II regions in the zone dominated by PAH emission (see Reach et al. 2006). In the same zone, lie the reflection nebulae NGC 7023 and the diffuse Galactic ISM as well. The dispersion in the colours of H II regions makes it difficult to separate them from SNRs and PNe. Statistically, the H II regions are more concentrated near the regions defined by low values of the two shortest IRAC channels and/or equivalently high values of the two longer IRAC wavelengths. The most intense PAH bands (6.2, 7.7, 8.6 $\mu$ m) are located in the 5.8 and 8.0 $\mu$ m channels and this may explain the colours of H II regions.

We compared the IRAC colours of our catalogued H II regions with the diffuse H II regions studied by Cohen et al. (2006). Upon conversion to their magnitude scale (Pahre et al. 2004), we find the IRAC-colour distributions to be mutually consistent.

5.2.2 Supernovae remnants

As a word of caution, since (especially young) SNRs are often associated with H II regions, they are often hard to discern and to measure photometrically given the crowding and confusion in the field. In the colour diagrams, the few detected SNRs lie between the H II regions and the PNe, generally closer to the H II regions.

Since the colours of pure synchrotron emission are never observed, there are several alternative emission mechanisms for the IR radiation that have been proposed by Reach et al. (2006) such as shocked molecular lines, shocked ionic lines, and PDR PAH emission. About half of their SNRs have colours consistent with molecular shocks, 17% are consistent with ionic shocks, and 22% with PAH emission from unshocked ISM. The others are thought to represent a mixture of shock types. All our 4 SNRs appear to belong to the class of shocked molecular emission (see the - grey - filled rectangle in the middle panel of Fig. 12), that is shocked molecular gas cooling mainly via MIR emission lines. Also, optically, SNRs appear as shock-heated emission nebulae (Gordon et al. 1999), confirming the prevalence of the two shock mechanisms described by Reach et al. (2006). The colours of our SNRs are also close to the colours of some H II regions. Note that the colours of the SNRs could depend of the epoch at which the SNR is observed (for instance because of the onset or decrease of shocks as they expand into the ISM).

5.2.3 Planetary nebulae

With few exceptions, catalogued PNe are confined to a region characterised by low values of the 5.8 and 8.0 $\mu$ m emission, the bandpasses where PAHs are believed to contribute substantially to the IR emission. Indeed, PNe spectra usually show an absence or very weak presence of PAH, as noted by Bernard-Salas et al. (2002) with ISO and by Bernard-Salas et al. (2004) and with Bernard-Salas et al. (2006) Spitzer. In the 4.5 $\mu$ m band, the [Mg iv] 4.485 $\mu$ m and [A vi] 4.530 $\mu$ m lines could give an additional contribution for high-excitation PNe (Cohen et al. 2005). Thus, in absence of detailed spectral information Spitzer colours can provide some diagnostics to help to identify PNe candidates (see also Hora et al. 2004).

6 The 24 $\mu$ m sources in M 33

Spitzer images provide a unique opportunity to compile vast catalogues of MIR discrete sources down to stellar luminosities for galaxies in the Local Group. In the present section we describe and discuss some features of the catalogue of 24 $\mu$ m sources (24Ss) which we have generated for M 33. In the first subsection, we describe the source selection criterion and flux measurements; in the second subsection, we investigate their nature in light of both theoretical and observational diagnostic diagrams; in the last subsection we present their luminosity function.

6.1 24 $\mu$ m source catalogue

To select and measure individual sources from the 24 $\mu$ m image, we used the SExtractor software (Bertin & Arnouts 1996). Using a convolution with a Gaussian filter we claim a detection when the source area is larger than 10 pixels and the peak signal-to-noise ratio is at least 10 times the local background. Guided by the galaxy pattern traced by the 24 $\mu$ m diffuse emission, we removed spurious sources such as foreground stars or artifacts due to map edge effects. The final catalogue comprises 515 objects; the positions are listed in Table 3. The brightest sources at 24 $\mu$ m are located in the central region and along the spiral arms. Fainter sources are more smoothly distributed but still follow the flocculent pattern of the galaxy.

6.2 Nature of the 24 $\mu$ m sources

Perhaps not surprisingly, sources in our 24 $\mu$ m catalogue turn out to have a higher detection rate than any of the other kinds of objects considered in the previous sections. This is particularly marked at 5.8 $\mu$ m where the detection rate for the 24 $\mu$ m sample is much higher than for H II regions (see Fig. 7) although, as seen in Fig. 9, the averaged SED of the 24Ss is similar to the one of H II regions.

The position of the 24Ss in the colour diagrams are illustrated in the top panels of Figs. 12-14. In Fig. 12, the region with the highest concentration matches well the one of H II regions. However the distribution of 24 $\mu$ m sources extends into the regions populated by SNRs and PNe. The comparison with the theoretical models indicates a paucity of sources with high extinction. However, as Fig. 12 shows, neither a pure blackbody, Cloudy, or the two DUSTY models can alone reproduce the colour distribution of the 24 $\mu$ m sources. Figure 13 shows a clear departure of the 24Ss sample from the expected narrow 4.5/5.8 colour dispersion. Such departure is particularly marked in the red tail of the distribution where both 24Ss and known-type sources tend to have colours similar to the PDR observed in the reflection nebulae NGC 7023.

The hybrid IRAC-24 $\mu$ m MIPS colour diagnostics of the selected sources are illustrated in Fig. 14. No 24S displays a 24/8.0 $\mu$ m flux ratio as high as the DUSTY models with shell inner temperature $T_{\rm in}$ = 300 K; the warmer models ( $T_{\rm in}$ = 600 K) seem more appropriate to describe their physical conditions. The range spanned by the 24/8.0 ratio in the 24 $\mu$ m sources is large but similar to the one covered by the catalogued H II regions, indicating that in both samples the contribution from PAH features may vary widely. So, 24Ss with both a low 4.5/8.0 and a low 24/8.0 ratio could well be H II regions with high PAH emission (see, for instance, the location of the radio-selected H II regions). The Cloudy H II region simulations seem to match well the colours of the 24Ss, in spite of their large scatter. On the contrary, the observations rule out most stellar colours: both pure blackbodies and the SB99 templates. However, as above, the general agreement between any single model and the 24Ss distribution in the colour diagrams is unsatisfactory; such a trend is probably due to a variable PAH component which is not considered in most of our templates (but see loci of NGC 7023 and the ISM). In the next section, we will select a subsample of 24Ss associated with the H ${\alpha }$ emission. These sources, likely to be optically visible H II regions, achieve a better agreement with low-extinction models.

6.3 Luminosity function of 24 $\mu$ m sources

The 24 $\mu$ m emission of M 33 within an ellipse of major axis 40' and axial ratio of 0.62 is 40.9 Jy. At a distance D = 840 kpc, such ellipse corresponds to a circle at galactocentric distance of 4.8 kpc inclined by 52 $^\circ$ with respect to our line of sight. The 24 $\mu$ m integrated emission is in good agreement with the value reported by Hinz et al. (2004) (see their Fig. 2) and implies a 24 $\mu$ m luminosity $(L = \nu F_\nu \times 4 \pi D^2)$ of 4.3 $\times$ 10⁴¹ erg s^-1. The contribution of the 515 discrete 24Ss amounts to 1.4 $\times$ 10⁴¹ erg s^-1, hence the diffuse component accounts for two thirds of the 24 $\mu$ m emission.

The cumulative luminosity function of the 515 discrete sources catalogued at 24 $\mu$ m is shown in Fig. 16. In this figure, the abscissas are reported as flux density at 24 $\mu$ m in mJy and also as total IR luminosity (TIR). To estimate the TIR luminosity, we follow the prescription of Calzetti et al. (2005) (see their Eq. (1)). The conversion involves the 24 $\mu$ m and the 8 $\mu$ m measurements. Since we do not have a detection at 8 $\mu$ m for all 24Ss, we compute the average 8 $\mu$ m/24 $\mu$ m flux ratio for the sources detected in both bands: the average is close to unity and therefore, in the lower panel of Fig. 16, which includes all 24Ss, we use $\log$ L(TIR) = $\log$ L(24 $\mu$ m) + 0.908. As a check, in the upper panel of Fig. 16, we plot the cumulative luminosity function only for the sources detected in both bands, using for each source the measured 8 $\mu$ m/24 $\mu$ m flux ratio: the shape and meaning (see below) of the two curves is quite compatible. The main effect, when using a constant average flux ratio, is a slight expansion of the range in L(TIR) by about 0.4 dex, together with a brightening by the same factor.

From the flattening of the faint end of the distribution, we estimate the completeness limit of the catalogue around 1 mJy, or an L(TIR) of 5 $\times$ 10³⁷ erg s^-1on the averaged scale. That is the bolometric luminosity of a B1.5 V star (Cox 2000) and so our listing should be quite complete even for faint obscured H II regions. Apart from the levelling off at low fluxes, as often observed for H II regions, open clusters, and associations (McKee & Williams 1997), the luminosity function displays a double slope behaviour, markedly steeper at the high luminosity tail. The change of slope, in the simplest scenarios, represents the change of regime between poor and rich clusters, where rich means numerous enough to represent fairly the high-mass IMF (Oey & Clarke 1998). In this framework, the transition point between the two regimes marks the luminosity of the single brightest star; below this value, the observed statistics is modified by the sampling variance. We find that the transition point occurs around $F_\nu$ (24 $\mu$ m) = 70 mJy, that is, in the averaged scale, an L(TIR) $\simeq$ 5 $\times$ 10³⁹ erg s^-1which, still bolometrically, corresponds to an O3 V star (Vacca et al. 1996). This implies: first, that most of the bright 24Ss are in fact luminous young stellar clusters and, second, that our L(TIR) scale cannot be grossly mistaken. From $F_\nu$ (24 $\mu$ m) = 1 to $F_\nu$ (24 $\mu$ m) = 70 mJy we fit a power index -0.55 $\pm$ 0.01 (plain - red - line) and, for larger values an index -1.09 $\pm$ 0.08 (dotted - green - line). It is easily shown that an index about unity, in the log-log cumulative distribution, implies for the rich galactic clusters a distribution $N(L) {\rm d}L \propto L^{-2} {\rm d}L$ or, equivalently, $N(n_*) {\rm d}n_* \propto n_*^{-2} {\rm d}n_*$ , n_* being the number of stellar members. Again, this is precisely the slope observed in the luminosity function of H II regions in late spirals (Caldwell et al. 1991), as well as the slope determined for Galactic clusters and associations, e.g. McKee & Williams (1997).

The brightest source reported in Fig. 16, at $F_\nu$ (24 $\mu$ m) $\simeq$ 1.8 Jy, would be roughly equivalent to an open cluster with around 3.5 $\times$ $10^7~L_\odot$ ; assuming that all members (0.06 to $90~M_\odot$ ) are on the main sequence, this makes a cluster of some $10^5~M_\odot$ , more than 10⁶ members, and more than 1000 ionising (> $15~M_\odot$ ) stars. On the other side, the faintest detected discrete 24Ss have $F_\nu$ (24 $\mu$ m) of 0.1-0.2 mJy, that is L(TIR) $\simeq$ 10³⁷ erg s^-1. This is about the bolometric luminosity of zero age main sequence B2 stars (Panagia 1973); so it is possible that these objects are also (the faintest) H II regions and our luminosity distribution appears to precisely match the whole range expected for ionised regions and their complexes. Anyway at low luminosity, especially below $10^4~L_\odot$ , the situation may be more intricate since also evolved stars can contribute substantially, more or less depending on the history of the region, to the population of IR sources; carbon giants, for example, at the distance of M 33 are expected to emit an average $F_\nu$ (24 $\mu$ m) $\simeq$ 0.25 mJy (Groenewegen et al. 2007). The nature of the 24Ss will be further explored, by investigating their spatial location within the galaxy and IR colours, in a forthcoming paper.

7 Star formation

7.1 Global star formation rates

In regions of moderate visual extinction, H ${\alpha }$ line emission is expected to be a reliable indicator of recent star formation. M 33 has globally a low extinction rate and therefore we can assess the performance of MIR emission as a star formation tracer, by comparing the SFR inferred from MIR emission with that derived from H ${\alpha }$ emission.

H ${\alpha }$ fluxes were measured on the map of Hoopes & Walterbos (2000) cited earlier (Sect. 2.3) and converted to SFR following Kennicutt (1998). We find a total SFR from H ${\alpha }$ , within 5 kpc from the centre, of 0.22 $M_\odot$ yr^-1 if no extinction corrections are taken into account. On average, this is a reasonable assumption since Tabatabaei et al. (2007b) found a perfect 3.6 cm-H ${\alpha }$ correlation for the thermally emitting regions in M 33. In any case, given that the diffuse H ${\alpha }$ emission amounts to 40% of the total (Hoopes & Walterbos 2000), an extinction correction of individual sources by A_V = 1 on average (as claimed by Devereux et al. 1997 and Israel & Kennicutt 1980), would increase the SFR in the same area to 0.3 $M_\odot$ yr^-1.

To estimate the SFR from the IR emission, we used two independent methods: we first estimate the TIR luminosity within a radius of 5 kpc using the data at 8.0 and 24 $\mu$ m. With a flux of 47.3 Jy, the integrated 8.0 $\mu$ m luminosity $L_\nu$ (8.0 $\mu$ m) is 4.0 $\times$ 10²⁸ erg s^-1 Hz^-1, corresponding to $\nu L_\nu(8)$ = 1.5 $\times$ 10⁴² erg s^-1. This is slightly higher than $L_\nu$ (24 $\mu$ m) = 3.5 $\times$ 10²⁸ erg s^-1 Hz^-1 (or $\nu L_\nu(24)$ = 4.4 $\times$ 10⁴¹ erg s^-1). Such a difference in the 8 and 24 $\mu$ m flux (47.3 vs. 40.9 Jy) is consistent with the IR SEDs measured in nearby galaxies (Dale et al. 2005), in which IR fluxes at 8.0 $\mu$ m often exceed those at 24 $\mu$ m. Using these values, Eq. (1) in Calzetti et al. (2005) yields an L(TIR) = 1.0 $\times$ $10^9~L_\odot$ . The IR SFR is usually computed from the FIR (40-120 $\mu$ m) luminosity. Calzetti et al. (2000) found that the ratio $L_{\rm IR}$ (1-1000 $\mu$ m)/ $L_{\rm IR}$ (40-120 $\mu$ m) is about 1.75. In our case this translates into a FIR luminosity of 5.8 $\times$ $10^8~L_\odot$ within a radius of 5 kpc in M 33. This is in good agreement with the value of 6.5 $\times$ $10^8~L_\odot$ found from the total IRAS fluxes reported by Rice et al. (1990), especially considering that we are including only the central 10 kpc in our estimate. Following the precepts of Buat & Xu (1996) for late spirals, that is SFR [ $M_\odot$ yr^-1] = 8 $\times$ 10^-44 L(FIR) with uncertainties of around 50%, we obtain a SFR equal to $0.18^{+0.18}_{-0.07}~M_\odot$ yr^-1. Within the uncertainties this estimate is compatible with those derived from H ${\alpha }$ emission (with and without extinction corrections). We obtain the same value from the TIR-SFR relation by Kennicutt (1998), taking into account the luminosity conversion (TIR vs. FIR).

The second method to derive the SFR from the IR emission involves the linear relation between radio and IR luminosities, and SFR (Yun et al. 2001). Wu et al. (2005) derived SFR directly from the 24 $\mu$ m luminosity (see their Eq. (1)): in our case, this translates into a SFR of 0.17 $M_\odot$ yr^-1. Using the 8 $\mu$ m luminosity (their Eq. (2)) gives a higher value of SFR, 0.26 $M_\odot$ yr^-1, even after subtracting the stellar contribution to the 8 $\mu$ m flux, $\sim$ 10%. Although within the errors of the 24 $\mu$ m and FIR results (from Rice et al. 1990), the 8 $\mu$ m value is $\la$ 40% higher than either the 24 $\mu$ m or the H ${\alpha }$ one. A similar trend was found by Calzetti et al. (2005) in which the 8 $\mu$ m SFR estimate can be significantly larger in weakly ionized regions such as the disk of M 33 taken globally. This is because the 8 $\mu$ m emission is produced by more than one mechanism, and thus does not trace SFR as accurately as other IR wavelengths.

In general then both MIR prescriptions for computing the SFR reach a satisfactory agreement with the H ${\alpha }$ -derived value and, beyond confirming the adopted SFR computing scheme, implies: a) that actively star forming sites are the main contributors to the MIR emission; b) that mean extinction is low also in the inner H II regions; c) that highly obscured sources do not contribute significantly to the MIR emission.

7.2 Star formation rates in 24 $\mu$ m sources

We then searched for H ${\alpha }$ emission at the location of the 24Ss. This was done in order to compare locally the SFRs from H ${\alpha }$ with those from the MIR, but also to check whether sources with and without an H ${\alpha }$ counterpart have on average the same IR colours. On the narrow-band (continuum subtracted) H ${\alpha }$ image, we performed the photometry of the 24Ss using the same technique described in Sect. 4.1. We find that 293 of the 24Ss are also detected in H ${\alpha }$ (within 3 $.\!\!^{\prime\prime}$ 6). An inspection of the H ${\alpha }$ image shows that most bright 24Ss with no H ${\alpha }$ counterpart actually lie near an H II region, with an offset which, though larger than the photometric errors, could still be accommodated in case of asymmetries of the H ${\alpha }$ shell. This is the case, for example, of some sources along the spiral arms. Some faint 24Ss sources might instead really be absent in the H ${\alpha }$ map. Indeed, the percentage of 24Ss undetected in H ${\alpha }$ gets higher close to the completeness limit of our survey. We will analyse this finding in more detail in a forthcoming paper. We note however that the luminosity function of the 24Ss with H ${\alpha }$ counterpart is totally compatible with the one for the whole sample presented in Sect. 6.3. This is because contamination of the 24 $\mu$ m sample by non star forming regions happens mostly below the completeness limit of the derived luminosity function.

To estimate the SFR in discrete sources, we adopted the same conversion methods used for the global SFRs and, in order to estimate the TIR luminosity following Calzetti's formula, we restrict our sample of 293 sources to the 186 sources which are also detected in the IRAC bands. The resulting SFRs are compared in Fig. 17, where the SFR is derived from H ${\alpha }$ without any average or individual extinction corrections and the FIR fluxes have been converted to SFR as in the previous subsection: SFR [ $M_\odot$ yr^-1] = 8 $\times$ 10⁴⁴ L(FIR). The scatter about the line of slope unity is large, roughly a factor of 5 ( $1\sigma$ ), and it is difficult to assess the presence of any systematic deviation. The scatter itself, given its magnitude, cannot be imputed to extinction only. Most of the variance is likely linked to the uncertainties intrinsic to the methods used to infer SFRs. A very similar plot can be obtained using the SFR estimated only from the 24 $\mu$ m emission (see previous subsection) of the discrete sources and is consequently not shown here.

We can compare the IR colours of the latter sample with those of the complementary sample made up by the 121 24Ss with no H ${\alpha }$ counterpart, selecting sources detected in all IRAC and MIPS-24 bands. One such diagram is in Fig. 18 and should be compared with the equivalent diagnostic diagram of Sect. 5. The 24Ss without H ${\alpha }$ actually seem to be less dusty sources than those emitting also in H ${\alpha }$ , a trend confirming that 24Ss with no H ${\alpha }$ are not more embedded into dust.

8 Summary and conclusions

This is the first in a series of papers aiming to investigate the star formation history in M 33 by means of the IR data from Spitzer. We retrieved and reduced IRAC and MIPS data producing maps roughly the size of the entire star forming galaxy disk. These were used to study the nature of the MIR emission, both globally (large scale structure of dust emission) and locally (by means of discrete sources). Our main results are the following:

References

9 Online Material

**Table 2:** Photometry of known type sources (the flag "-99.0'' is used when the photometric centre is farther than 3 $.\!\!^{\prime\prime}$ 6 from the nominal position).
Type	Num.	RA (J2000)	Dec (J2000)		3.6 $\mu$ m		4.5 $\mu$ m		5.8 $\mu$ m		8.0 $\mu$ m		24 $\mu$ m		H ${\alpha }$
		( $^\circ$ )	( $^\circ$ )	$F_\nu$ (mJy)	$\delta r$	$F_\nu$ (mJy)	$\delta r$	$F_\nu$ (mJy)	$\delta r$	$F_\nu$ (mJy)	$\delta r$	$F_\nu$ (mJy)	$\delta r$	F (10^-14 erg s^-1)	$\delta r$
ISO	1	01:33:59.3	30:35:49.2	2.779	2.38	2.248	2.06	24.410	1.86	21.504	1.77	86.133	1.33	161.110	1.01
ISO	2	01:33:09.8	30:27:25	4.570	1.60	3.640	1.47	13.660	1.63	46.120	0.57	106.790	1.73	59.330	0.60
ISO	3	01:33:44.5	30:44:38	3.350	1.14	1.507	1.39	9.098	1.16	24.896	0.95	204.660	0.41	89.796	0.86
ISO	4	01:33:45.5	30:36:51.1	2.000	1.97	3.220	1.51	11.200	2.11	30.649	1.93	57.035	1.94	62.180	1.39
ISO	5	01:33:35.5	30:39:30.5	1.598	1.30	1.566	1.20	10.291	1.53	27.896	1.43	95.377	0.88	18.056	0.76
ISO	6	01:33:35.5	30:39:30	4.060	1.23	1.566	0.79	10.291	1.12	27.896	1.02	95.377	0.49	18.056	0.60
ISO	7	01:33:28.8	30:40:24.7	4.303	1.31	4.589	1.28	21.656	1.81	65.556	1.17	331.663	0.61	84.178	1.47
ISO	8	01:33:33.9	30:41:28.3	6.338	1.89	6.683	1.57	125.460	2.38	71.506	2.21	1434.670	0.87	394.332	2.17
ISO	9	01:33:55.3	30:45:22	1.226	1.72	1.184	1.68	6.228	1.57	18.322	1.91	64.093	1.16	88.720	0.76
ISO	10	01:34:00.2	30:40:48.6	4.552	0.85	5.278	0.89	26.941	0.97	78.783	0.88	493.010	0.83	19.379	0.32
ISO	14	01:34:10.9	30:36:18.1	4.740	1.22	0.921	1.67	5.236	1.63	13.459	1.71	48.906	0.92	72.270	2.10
ISO	16	01:33:36.6	30:20:13.4	3.220	0.84	2.480	0.53	10.200	0.65	11.916	0.53	79.540	0.82	115.650	0.09
ISO	19	01:33:16.5	30:52:49.1	4.883	0.80	10.097	0.82	27.897	0.85	70.689	0.71	942.423	0.97	102.805	0.59
ISO	21	01:33:16.3	30:56:43.8	0.402	2.50	0.488	2.48	1.315	2.14	3.164	1.91	-99.0	-99.0	82.221	2.19
ISO	23	01:34:33.5	30:46:50.5	14.115	2.50	12.607	1.96	25.052	0.93	183.911	1.06	-99.0	-99.0	-99.0	-99.0
ISO	24	01:34:32.1	30:46:59.9	9.463	0.30	5.080	0.97	55.272	0.89	167.831	0.82	264.127	1.59	313.513	0.69
ISO	25	01:34:16.4	30:51:55.1	3.162	1.11	3.228	1.14	35.200	1.19	19.684	1.36	224.650	0.63	98.304	0.47
Hra	5	01:33:16.00	+30:56:45.9	4.570	2.62	3.640	2.47	13.660	1.26	46.120	1.15	106.790	0.92	59.330	1.13
Hra	7	01:33:33.62	+30:32:08.1	4.938	1.04	10.096	1.06	48.730	1.17	71.289	0.99	996.074	0.43	100.845	0.84
Hra	10	01:33:36.53	+30:20:14.4	1.598	0.70	1.542	0.75	9.788	0.91	27.048	0.66	94.753	0.30	18.056	0.85
Hra	11	01:33:39.18	+30:38:06.9	3.220	1.50	2.480	1.21	10.200	0.84	14.362	0.85	79.540	0.64	115.650	0.74
Hra	12	01:33:42.96	+30:44:40.6	0.106	0.59	0.177	0.61	0.227	0.65	0.258	0.88	0.704	1.59	-99.0	-99.0
Hra	13	01:33:43.64	+30:39:07.1	0.074	1.79	0.262	1.77	1.519	1.68	3.996	1.89	33.199	2.24	121.820	0.83
Hra	14	01:33:44.49	+30:44:38.4	1.424	1.50	1.130	1.10	7.748	2.09	23.673	2.44	22.730	0.56	38.496	0.07
Hra	16	01:33:47.86	+30:43:52.6	1.650	1.67	1.482	1.75	9.381	1.54	25.793	1.30	66.974	1.25	89.796	0.84
Hra	17	01:33:50.16	+30:33:46.8	0.768	1.47	0.684	1.55	5.613	1.96	15.975	1.78	16.387	0.60	124.330	0.38
Hra	19	01:33:51.34	+30:43:52.8	0.169	1.91	0.254	2.22	2.035	1.73	6.063	1.83	7.250	1.80	46.670	0.29
Hra	20	01:33:52.57	+30:39:18.4	2.219	1.63	2.290	2.32	11.435	1.57	31.355	1.33	48.001	0.61	39.910	2.83
Hra	22	01:33:57.47	+30:42:16.2	8.613	1.35	94.480	1.20	115.710	1.24	102.012	1.49	64.674	1.11	52.961	1.22
Hra	27	01:34:01.01	+30:43:55.4	2.779	2.78	2.248	2.45	8.453	2.23	21.504	1.96	86.133	1.37	161.110	1.11
Hra	28	01:34:02.21	+30:38:40.7	4.470	0.53	5.188	0.54	26.941	0.59	78.783	0.26	493.010	0.05	19.379	0.33
Hra	29	01:34:06.38	+30:41:45.6	1.266	0.70	1.155	0.61	6.595	0.91	50.250	1.07	23.085	0.72	23.758	0.70
Hra	33	01:34:13.73	+30:34:51.4	1.000	1.55	0.924	1.28	5.719	1.33	129.290	1.42	55.358	0.29	72.270	0.47
Hra	37	01:34:33.13	+30:46:57.3	7.970	0.58	0.848	0.68	5.545	0.77	15.175	0.70	101.800	0.18	122.040	1.47
Hra	40	01:34:41.04	+30:43:29.5	0.364	0.96	0.442	0.88	2.860	1.08	5.227	0.98	59.380	0.80	18.960	0.35
HII	1	1:32:29.5	30:36:07.9	0.119	1.95	0.181	1.92	0.330	1.27	0.915	1.47	-99.0	-99.0	8.850	0.46
HII	9	1:32:45.9	30:41:35.5	0.168	1.00	0.080	0.92	0.130	0.58	1.009	0.52	1.050	0.28	4.400	0.12
HII	17	1:33:10.8	30:18:08.5	0.080	0.96	0.050	0.55	0.090	0.98	0.700	0.78	-99.0	-99.0	4.080	0.25
HII	19	1:33:11.2	30:45:16.4	2.916	0.66	2.941	0.44	10.046	1.22	25.664	1.29	177.960	0.63	117.495	0.24
HII	26	1:33:19.0	30:58:14.3	0.199	0.68	0.088	0.39	0.448	0.25	1.800	1.06	0.242	1.01	4.171	0.22
HII	29	1:33:28.1	31:00:17.2	0.150	1.87	0.136	1.82	0.421	2.28	1.272	2.03	1.060	1.84	13.270	1.15
HII	30	1:33:29.0	30:40:24.8	4.137	1.62	4.457	1.34	21.040	1.72	63.637	1.78	633.390	1.69	82.292	0.24
HII	37	1:33:44.8	31:02:22.0	0.077	2.52	0.066	2.02	0.217	1.55	0.416	1.77	1.378	2.68	13.316	1.37
HII	39	1:33:46.3	30:52:15.0	0.204	0.56	0.195	0.63	1.063	0.69	2.775	0.63	6.940	0.64	5.044	0.31
HII	40	1:33:47.0	30:27:22.8	0.620	0.41	0.410	0.76	1.650	0.27	7.860	0.83	6.190	0.55	21.650	0.18
HII	47	1:33:59.9	30:32:44.3	0.903	0.36	0.950	0.10	3.600	0.20	13.374	0.35	24.020	1.21	40.020	0.30
HII	49	1:34:01.7	30:23:00.6	0.240	2.58	0.120	2.31	0.196	2.43	0.358	1.55	0.634	2.02	2.910	0.67
HII	51	1:34:04.3	31:02:17.9	0.044	1.43	0.031	1.43	0.166	2.35	0.442	1.82	0.610	2.05	4.421	0.38
HII	52	1:34:06.7	30:48:56.4	0.326	0.75	0.302	0.54	1.757	1.24	5.450	1.48	8.930	1.92	24.962	0.43
HII	53	1:34:09.4	30:34:17.0	0.820	1.61	0.597	1.66	2.728	2.19	7.538	2.41	-99.0	-99.0	23.980	0.31
HII	55	1:34:14.4	30:27:40.3	0.120	1.62	0.041	2.39	0.185	0.66	1.186	2.13	-99.0	-99.0	0.248	0.32
HII	62	1:34:36.1	30:45:59.6	0.168	1.50	0.110	1.20	0.488	1.20	1.137	1.15	1.609	2.38	4.619	2.12
HII	64	1:34:37.4	30:34:54.3	0.369	0.93	0.445	0.84	1.935	0.84	5.193	1.08	59.380	1.43	18.960	0.16
HII	65	1:34:38.5	30:32:52.3	0.034	0.35	0.027	0.12	0.149	0.61	0.240	0.53	0.710	1.01	1.080	0.34
HII	67	1:34:39.3	31:02:25.0	0.051	1.93	0.041	1.84	0.294	1.96	0.854	2.05	-99.0	-99.0	6.169	0.64
HII	68	1:34:39.5	30:31:14.2	0.128	0.83	0.116	0.76	0.684	0.66	1.972	0.31	21.350	1.02	1.090	0.33
HII	69	1:34:42.2	30:24:00.5	0.043	0.38	0.046	0.29	0.161	0.32	0.310	0.31	0.210	0.39	1.620	0.28
HII	70	1:34:42.5	30:55:44.5	0.410	0.59	0.440	0.89	1.410	0.15	3.199	0.72	-99.0	-99.0	1.999	0.12
HII	71	1:34:45.5	30:42:24.4	0.200	0.41	0.159	0.18	0.551	0.24	1.590	0.21	1.630	0.75	4.046	0.49
HII	72	1:34:49.2	30:37:27.5	0.052	0.85	0.041	0.81	0.278	0.74	0.831	1.08	2.370	1.40	0.430	0.63
HII	75	1:35:01.6	30:40:02.3	0.069	0.38	0.053	0.35	0.180	0.64	0.940	0.42	-99.0	-99.0	1.456	0.49
HII	76	1:35:02.4	31:00:43.4	0.067	1.17	0.044	1.00	0.153	1.03	0.141	1.16	-99.0	-99.0	2.687	0.70
SNo	25	1:33:23.8	30:26:11.6	0.550	1.40	0.380	0.96	0.890	0.81	1.325	1.87	1.947	1.55	3.310	0.95
SNo	43	1:33:41.7	30:21:01.8	3.590	2.56	2.090	2.21	4.060	2.09	18.670	0.61	11.060	0.54	14.907	1.82
SNo	53	1:33:54.5	30:33:47.7	0.134	2.67	0.070	2.84	0.300	2.71	0.733	2.85	-99.0	-99.0	-99.0	-99.0
SNR	13	1:33:23.78	30:26:11.60	0.550	1.42	0.380	0.99	0.890	1.00	1.319	1.92	1.947	1.68	3.310	0.97
PNe	4	01:32:39.80	+30:37:41.0	0.017	0.23	0.018	0.79	0.023	1.16	0.066	0.69	0.000	6.74	0.164	0.18
PNe	60	01:33:44.38	+30:20:23.7	0.050	2.64	0.035	2.41	0.058	2.73	0.039	2.45	0.361	0.81	0.220	0.19
PNe	79	01:33:54.93	+30:47:13.4	0.156	1.61	0.084	1.46	0.107	1.86	0.099	1.01	0.000	7.18	-99.0	-99.0
PNe	85	01:33:58.38	+30:55:05.2	0.050	2.34	0.041	1.71	0.217	1.61	0.698	1.75	0.389	1.29	0.676	0.87
PNe	106	01:34:12.15	+30:28:57.1	0.160	2.65	0.090	2.85	0.130	2.56	0.074	2.90	0.379	3.43	0.181	1.37
PNe	112	01:34:15.15	+30:44:57.4	0.189	2.04	0.224	2.10	0.251	2.15	0.152	2.34	0.000	7.62	0.185	0.06
PNe	128	01:34:25.55	+30:40:10.9	0.248	0.71	0.157	0.65	0.153	0.39	0.207	0.28	0.394	0.42	0.275	0.37
PNe	133	01:34:31.49	+31:05:24.0	0.023	0.54	0.012	0.69	0.067	0.48	0.152	0.07	0.000	6.63	0.148	0.17
PNe	139	01:34:37.89	+30:27:00.7	0.140	2.20	0.060	2.20	0.114	1.73	0.160	0.88	0.113	0.60	0.210	0.20

Table 3: Photometry of 24 $\mu$ m sources (the flag "-99.0'' is used when the photometric centre is farther than 3 $.\!\!^{\prime\prime}$ 6 from the nominal position).
Num. RA (J2000) Dec (J2000) 3.6 $\mu$ m 4.5 $\mu$ m 5.8 $\mu$ m 8.0 $\mu$ m 24 $\mu$ m H ${\alpha }$

( $^\circ$ ) ( $^\circ$ ) $F_\nu$ (mJy) $\delta r$ $F_\nu$ (mJy) $\delta r$ $F_\nu$ (mJy) $\delta r$ $F_\nu$ (mJy) $\delta r$ $F_\nu$ (mJy) $\delta r$ F (10^-14 erg s^-1) $\delta r$

1 23.3749767 30.3099105 0.2 2.846 0.13 2.799 0.76 2.934 2.71 2.762 23.59 0.022 -99.0 -99.0

2 23.3614272 30.2907556 0.06 0.646 0.069 0.54 0.33 0.824 1.46 0.956 0.75 0.0 0.32 0.2

3 23.3721103 30.3016896 0.21 1.196 0.1 1.001 0.58 0.522 2.27 0.796 4.59 0.022 5.583 0.24

4 23.3329204 30.3053012 -99.0 -99.0 -99.0 -99.0 0.364 0.527 0.963 1.04 1.286 0.122 -99.0 -99.0

5 23.3358182 30.3040334 0.021 0.72 0.052 0.73 0.105 0.652 -99.0 -99.0 0.7 0.073 -99.0 -99.0

6 23.4435711 30.3038256 0.046 0.592 0.04 0.586 0.148 0.62 0.14 0.643 0.29 0.002 -99.0 -99.0

7 23.4487444 30.3048739 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.67 0.077 -99.0 -99.0

8 23.4024463 30.3367871 3.22 0.433 2.48 0.557 4.57 0.989 11.998 0.954 79.54 0.001 53.569 0.424

9 23.3768792 30.3196512 0.051 1.954 0.042 2.02 0.21 1.599 2.33 0.926 0.82 0.204 1.16 2.558

10 23.3843288 30.3366678 0.205 2.028 0.191 1.907 1.951 1.054 5.84 0.756 4.258 0.16 2.59 1.505

11 23.48185 30.330103 0.16 0.647 0.14 0.489 0.62 0.823 2.13 1.002 3.64 0.031 11.01 0.243

12 23.4718432 30.3314455 0.074 1.463 0.053 1.31 0.11 0.56 0.47 0.774 5.24 0.016 -99.0 -99.0

13 23.3860886 30.3334663 -99.0 -99.0 0.027 0.932 0.26 1.079 2.06 1.164 3.54 0.121 1.6 1.766

14 23.4064918 30.3470677 0.65 2.978 0.22 2.634 2.52 0.68 14.48 0.386 16.9 0.229 72.49 0.929

15 23.3513249 30.3401814 0.23 2.685 0.16 1.825 0.137 0.609 0.14 0.456 1.05 0.001 -99.0 -99.0

16 23.3882322 30.3414916 -99.0 -99.0 -99.0 -99.0 0.28 0.32 2.08 0.519 0.9 0.002 4.189 0.71

17 23.4370169 30.3513656 1.15 1.087 0.86 0.966 1.4 0.939 1.374 1.071 2.04 0.003 2.951 2.055

18 23.4379955 30.3604276 0.48 1.602 0.4 1.196 1.39 1.172 4.22 1.186 17.56 0.009 22.336 0.215

19 23.410961 30.3512346 0.669 0.362 0.765 0.311 1.17 0.594 1.4 0.622 3.05 0.043 -99.0 -99.0

20 23.2919766 30.3854636 -99.0 -99.0 0.7 2.58 4.79 0.849 15.14 2.412 25.14 0.329 21.901 0.777

21 23.3234794 30.3571074 0.65 1.11 0.49 0.847 0.19 0.281 1.9 0.639 1.02 0.11 0.056 0.51

22 23.414503 30.3611675 0.22 0.289 0.24 0.483 0.2 0.562 0.29 0.613 0.7 0.002 -99.0 -99.0

23 23.4145537 30.3787926 0.47 1.408 0.42 1.42 4.67 1.413 3.556 1.234 19.4 0.041 3.49 1.477

24 23.4855241 30.3733786 -99.0 -99.0 -99.0 -99.0 1.43 2.456 11.96 2.034 4.17 0.055 10.07 0.242

25 23.4387472 30.3656494 -99.0 -99.0 -99.0 -99.0 0.208 0.814 0.52 0.854 1.49 0.002 -99.0 -99.0

26 23.3056383 30.3771194 0.11 2.189 0.07 2.383 1.11 1.69 11.45 2.584 9.12 0.029 9.58 2.557

27 23.5564787 30.3681733 0.12 2.343 0.048 0.428 0.05 0.339 0.234 0.381 1.03 0.001 -99.0 -99.0

28 23.2961441 30.3771633 -99.0 -99.0 -99.0 -99.0 0.56 2.7 5.5 2.201 1.11 0.097 -99.0 -99.0

29 23.2797677 30.3863205 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 7.93 1.122 6.74 0.037 31.62 2.011

30 23.4006862 30.3774629 -99.0 -99.0 -99.0 -99.0 0.16 0.3 0.69 0.453 2.0 0.001 0.472 1.303

31 23.5000231 30.37729 0.13 0.697 0.12 0.685 0.4 1.315 0.96 1.426 0.38 0.001 -99.0 -99.0

32 23.2887017 30.3916345 0.56 0.913 0.42 1.35 1.203 0.875 3.357 0.7 19.81 1.467 17.273 2.536

33 23.3178801 30.3847881 3.3 0.921 2.22 0.893 1.82 0.948 1.84 0.824 2.72 0.001 0.86 0.899

34 23.3616848 30.3870248 0.89 0.621 1.34 0.575 1.8 0.603 2.15 0.638 2.08 0.032 -99.0 -99.0

35 23.4989082 30.3848985 0.116 0.891 0.069 0.948 0.197 1.048 0.61 1.738 0.3 0.002 2.6 2.811

36 23.2737497 30.3907547 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 2.46 1.249 3.27 0.077 -99.0 -99.0

37 23.3498559 30.4274082 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 97.33 0.006 -99.0 -99.0

38 23.5540474 30.3917149 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.35 0.001 -99.0 -99.0

39 23.4097494 30.3990514 0.14 0.179 0.07 0.535 0.64 0.651 2.42 0.709 2.92 0.025 0.65 0.32

40 23.2910806 30.4571431 4.57 0.885 3.64 0.82 13.66 2.357 45.75 1.143 106.79 2.577 59.33 0.5

41 23.2954134 30.4612809 3.41 1.515 2.61 1.567 16.95 1.522 50.78 1.518 85.82 0.127 29.423 1.511

42 23.4877339 30.4195854 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.003 0.653 0.53 0.117 2.98 2.508

43 23.5439212 30.432297 0.18 0.798 0.11 0.457 0.96 0.738 4.78 0.831 4.78 0.001 3.597 0.325

44 23.54527 30.4267949 0.038 0.739 0.027 0.725 0.19 0.432 1.8 0.526 1.15 0.055 1.457 2.145

45 23.5583747 30.4298619 0.5 0.861 0.38 0.859 1.39 1.087 1.495 1.186 3.05 0.033 3.42 2.687

46 23.397946 30.4325781 0.54 0.654 0.35 0.479 1.81 0.728 5.65 0.622 7.55 0.014 7.27 0.314

47 23.5581556 30.5800716 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 199.76 0.08 -99.0 -99.0

48 23.3472539 30.4430213 -99.0 -99.0 -99.0 -99.0 0.64 1.157 1.196 1.249 0.851 0.152 2.59 2.223

49 23.2869175 30.4975933 -99.0 -99.0 -99.0 -99.0 21.73 1.073 124.86 2.16 75.65 0.065 136.24 0.475

50 23.5539497 30.4581009 0.26 2.823 0.19 2.545 0.38 0.966 4.85 1.384 14.3 0.0 -99.0 -99.0

51 23.4121779 30.4713349 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 25.72 0.009 1.65 2.399

52 23.4840991 30.4526648 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.7 0.229 -99.0 -99.0

53 23.4456607 30.4564383 0.62 0.728 0.294 0.143 0.987 0.377 2.745 0.477 6.19 0.001 21.65 0.371

54 23.4854658 30.4547352 0.093 0.821 0.066 0.836 0.65 0.693 1.816 0.684 3.031 0.978 16.679 1.912

55 23.4825356 30.4578157 2.628 0.683 2.788 0.668 2.771 0.753 2.649 0.713 1.421 0.127 -99.0 -99.0

56 23.5652741 30.4626984 1.66 1.064 1.23 0.84 1.3 0.838 4.11 0.667 11.23 0.004 0.446 2.689

57 23.5485285 30.4544927 0.2 2.315 -99.0 -99.0 0.57 0.444 4.47 0.639 0.87 0.088 1.46 0.398

58 23.238228 30.457635 0.54 1.667 0.19 1.723 0.61 1.159 6.86 0.962 1.41 0.048 -99.0 -99.0

59 23.4668067 30.4518772 0.23 1.505 0.26 1.019 0.21 1.152 0.45 0.758 0.36 0.001 -99.0 -99.0

60 23.3902028 30.5356536 -99.0 -99.0 -99.0 -99.0 71.22 1.952 395.8 0.32 250.56 0.411 136.42 1.246

61 23.5639999 30.4711516 2.95 0.323 3.55 0.284 4.61 0.609 4.247 0.323 17.56 0.0 1.805 0.192

62 23.5964784 30.4621603 -99.0 -99.0 -99.0 -99.0 0.031 0.722 0.358 1.745 0.29 0.001 -99.0 -99.0

63 23.6059902 30.4649241 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.155 1.481 0.3 0.129 -99.0 -99.0

64 23.295885 30.4991531 -99.0 -99.0 -99.0 -99.0 5.68 0.751 15.95 0.573 23.08 0.162 -99.0 -99.0

65 23.4373183 30.6031596 -99.0 -99.0 -99.0 -99.0 75.28 0.166 -99.0 -99.0 163.3 0.05 -99.0 -99.0

66 23.6070908 30.4717673 0.08 0.558 0.13 0.564 0.192 0.795 0.16 0.728 0.78 0.001 -99.0 -99.0

67 23.5731509 30.4732955 0.25 0.953 0.12 0.584 0.169 0.68 0.63 0.318 1.11 0.001 -99.0 -99.0

68 23.2896084 30.4871826 0.29 1.955 0.16 1.435 1.36 0.659 1.911 0.672 3.099 0.097 0.4 0.392

69 23.3472862 30.5266611 0.74 0.692 0.51 0.801 5.48 0.346 6.445 0.784 14.31 0.407 12.63 0.447

70 23.3742461 30.530412 18.63 0.799 8.55 2.92 98.58 0.532 -99.0 -99.0 300.19 1.624 146.03 1.68

71 23.4139809 30.49824 0.27 2.12 0.09 1.431 1.32 1.484 10.17 1.014 3.82 0.186 -99.0 -99.0

72 23.4523366 30.6610505 175.3 1.792 102.97 2.683 148.28 1.079 -99.0 -99.0 281.52 0.302 -99.0 -99.0

73 23.266931 30.4825374 0.16 2.151 -99.0 -99.0 -99.0 -99.0 0.21 0.265 1.1 0.001 3.16 0.933

74 23.301739 30.5073557 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 31.08 1.263 -99.0 -99.0

75 23.4985862 30.5639235 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 40.67 0.82 104.46 2.004

76 23.4844389 30.4914555 1.14 1.222 0.73 1.264 1.04 1.36 7.74 1.289 5.23 0.017 -99.0 -99.0

77 23.39711 30.4975299 0.74 1.51 0.35 1.638 3.52 1.431 3.088 1.283 11.54 0.01 4.919 1.132

78 23.2681679 30.4922758 -99.0 -99.0 -99.0 -99.0 0.36 1.76 1.158 1.377 1.35 0.135 3.22 2.78

79 23.492846 30.5371378 -99.0 -99.0 -99.0 -99.0 14.97 0.719 115.19 0.405 28.05 0.367 10.484 2.145

80 23.2518713 30.512725 -99.0 -99.0 0.72 2.157 8.12 2.538 39.52 2.702 11.698 0.573 45.469 0.349

81 23.2813558 30.5168685 0.51 0.574 0.4 0.829 2.95 0.65 3.481 1.023 30.03 0.58 7.385 0.281

82 23.457549 30.4914213 2.25 1.105 1.7 1.165 1.5 1.155 4.58 0.942 1.42 0.098 5.62 1.089

83 23.4086361 30.504008 0.095 1.45 0.063 1.468 0.95 2.886 3.161 2.91 0.77 2.76 22.763 2.52

84 23.4698216 30.6532793 121.02 2.091 94.48 1.707 -99.0 -99.0 -99.0 -99.0 333.39 2.151 -99.0 -99.0

85 23.5536876 30.4938742 1.26 0.149 2.4 0.309 3.11 0.516 3.56 0.454 3.07 0.0 0.157 2.899

86 23.2613307 30.4928575 -99.0 -99.0 -99.0 -99.0 1.489 2.836 0.801 1.873 1.05 0.002 3.673 0.509

87 23.3278802 30.4928602 0.22 0.409 0.19 0.431 0.17 0.489 3.897 1.014 0.93 0.003 -99.0 -99.0

88 23.4088097 30.5005227 -99.0 -99.0 0.068 1.46 0.46 0.79 1.182 0.669 1.98 0.077 -99.0 -99.0

89 23.5064687 30.5122019 0.38 2.851 0.13 2.681 2.5 1.2 12.1 1.156 4.96 0.001 -99.0 -99.0

90 23.4154371 30.5039219 -99.0 -99.0 -99.0 -99.0 2.54 0.344 10.51 0.348 4.139 0.094 -99.0 -99.0

91 23.412667 30.5434291 0.252 0.653 0.219 0.585 29.66 0.305 74.77 1.577 61.36 0.496 65.3 1.3

92 23.3163221 30.500713 -99.0 -99.0 0.05 0.34 0.167 0.299 0.239 0.253 0.98 0.005 -99.0 -99.0

93 23.254073 30.5177006 0.88 0.747 0.61 0.305 4.86 0.919 16.64 1.419 9.227 0.043 53.9 2.256

94 23.2214737 30.4996198 -99.0 -99.0 -99.0 -99.0 0.276 1.945 0.265 1.559 0.46 0.001 5.129 1.937

95 23.508331 30.5014567 0.53 0.348 0.4 0.381 0.24 0.298 0.46 0.462 0.4 0.001 -99.0 -99.0

96 23.4122382 30.5205292 2.44 2.35 3.29 1.503 4.88 1.485 6.35 1.43 11.57 1.584 -99.0 -99.0

97 23.4749445 30.5517846 0.87 2.7 1.35 2.681 59.46 2.646 3.382 2.869 133.93 0.636 205.1 0.617

98 23.3537245 30.5146282 0.23 2.49 0.04 1.815 0.67 2.743 2.544 2.807 3.18 0.0 13.02 2.318

99 23.6647902 30.520899 0.35 1.869 0.16 1.439 2.59 1.599 9.37 1.683 21.35 0.011 1.09 0.833

100 23.4355158 30.5343999 5.25 2.317 1.65 2.619 8.89 1.388 40.76 2.247 14.65 0.014 2.438 1.65

101 23.5920186 30.5218368 -99.0 -99.0 -99.0 -99.0 1.79 1.288 6.79 1.17 8.89 0.001 -99.0 -99.0

102 23.4374512 30.518462 0.09 1.256 0.055 1.134 1.43 1.304 9.1 0.749 1.67 0.002 -99.0 -99.0

103 23.2701529 30.5158071 -99.0 -99.0 -99.0 -99.0 0.82 0.248 4.756 0.433 0.98 0.001 0.741 1.822

104 23.5721108 30.5620107 7.97 0.588 3.8 0.7 41.31 1.269 129.61 0.502 101.8 0.592 122.04 1.412

105 23.471327 30.5157448 0.32 2.923 -99.0 -99.0 0.59 0.764 0.819 0.474 1.04 0.001 0.303 2.72

106 23.4040552 30.5173943 0.43 0.348 0.96 0.49 1.73 0.681 1.743 0.632 1.98 0.001 -99.0 -99.0

107 23.2774335 30.5245107 0.27 0.952 0.12 0.606 0.84 0.494 2.131 0.537 2.41 0.059 2.571 1.092

108 23.3318144 30.5180844 0.204 0.275 0.32 0.115 0.33 0.268 0.46 0.754 0.72 0.002 -99.0 -99.0

109 23.5415395 30.5323582 1.29 0.773 0.63 0.671 2.65 1.491 15.73 0.612 8.95 0.014 15.72 0.604

110 23.2452382 30.5289389 -99.0 -99.0 -99.0 -99.0 1.44 2.648 9.04 1.004 2.88 0.003 -99.0 -99.0

111 23.4849398 30.521593 -99.0 -99.0 -99.0 -99.0 0.2 1.368 0.366 0.773 1.14 0.003 -99.0 -99.0

112 23.2703065 30.5205838 -99.0 -99.0 -99.0 -99.0 0.235 0.397 0.823 0.566 0.718 0.021 2.797 2.522

113 23.4444628 30.5437413 3.99 0.655 1.15 1.562 4.189 1.038 18.641 0.687 58.94 0.284 -99.0 -99.0

114 23.4990498 30.5459143 1.47 2.417 0.95 2.362 -99.0 -99.0 28.15 2.314 24.02 1.083 40.02 0.359

115 23.5569419 30.5620427 12.5 2.242 9.31 2.27 8.269 1.338 169.48 2.44 233.02 0.596 65.698 0.847

116 23.4184798 30.5264105 -99.0 -99.0 -99.0 -99.0 1.19 1.196 1.853 0.427 1.51 0.062 -99.0 -99.0

117 23.4358347 30.522334 0.176 0.92 0.174 1.434 0.726 0.214 1.997 0.365 0.842 0.125 -99.0 -99.0

118 23.5937772 30.5448368 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 15.66 0.015 3.548 2.293

119 23.5093193 30.52338 0.91 2.403 0.42 2.069 0.5 1.348 1.61 0.426 0.51 0.088 6.01 1.091

120 23.2567542 30.5312275 0.08 1.006 0.06 1.07 0.56 1.086 1.95 1.389 4.33 0.022 3.35 2.21

121 23.3110259 30.5437026 0.52 2.261 -99.0 -99.0 1.59 1.832 3.432 1.224 12.36 0.037 -99.0 -99.0

122 23.5068489 30.5970729 -99.0 -99.0 -99.0 -99.0 10.42 1.884 6.396 1.662 26.69 0.191 11.229 0.393

123 23.2406684 30.533238 0.22 1.363 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 2.44 0.003 -99.0 -99.0

124 23.4307023 30.5298609 0.523 2.306 0.36 2.593 0.88 1.034 2.48 0.53 2.02 0.014 1.364 0.741

125 23.2699196 30.5323766 0.26 0.612 0.1 0.5 1.36 1.135 3.942 0.646 2.99 0.032 6.592 0.363

126 23.2724933 30.5273496 1.833 0.442 1.516 0.443 1.43 0.386 1.059 0.518 0.38 0.001 -99.0 -99.0

127 23.4488423 30.551252 5.29 1.189 3.36 1.408 7.312 0.333 17.945 0.126 81.43 0.001 35.135 0.844

128 23.2576171 30.5424959 0.35 2.146 0.23 0.985 5.13 0.685 4.473 0.338 5.36 0.134 -99.0 -99.0

129 23.5013484 30.5725881 4.3 2.432 2.81 2.333 27.58 1.469 -99.0 -99.0 3.08 2.746 81.834 0.589

130 23.6751983 30.5403655 0.1 0.355 -99.0 -99.0 0.45 0.443 2.91 0.375 1.155 0.049 2.22 2.378

131 23.4592086 30.5634396 1.53 0.83 1.11 1.136 2.234 0.508 15.067 0.757 6.838 0.551 28.327 0.405

132 23.2326878 30.5413206 0.4 1.803 0.441 0.358 0.527 0.443 1.292 0.664 5.415 0.616 17.741 0.603

133 23.3254282 30.5561522 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 17.98 0.014 -99.0 -99.0

134 23.5330369 30.5465901 0.126 0.692 0.17 0.681 0.968 0.392 2.56 0.684 10.8 0.101 1.53 1.739

135 23.2550544 30.5461019 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.779 0.107 0.415 1.278

136 23.5951658 30.5693594 0.33 0.546 0.47 0.766 2.21 0.735 3.833 0.513 43.9 1.253 2.26 0.655

137 23.4600168 30.5420632 4.37 2.58 3.46 2.355 4.68 2.141 2.214 2.13 3.91 0.026 4.857 0.455

138 23.3221538 30.5362579 1.32 0.449 0.934 0.466 0.77 0.439 0.75 0.523 0.41 0.0 -99.0 -99.0

139 23.58378 30.5509049 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 13.8 0.907 6.49 0.033 -99.0 -99.0

140 23.6781752 30.5426413 0.116 1.248 0.173 1.347 0.369 0.767 0.868 0.823 1.241 0.123 -99.0 -99.0

141 23.2514388 30.5408204 0.21 1.598 -99.0 -99.0 1.79 0.267 10.33 0.771 1.37 0.001 -99.0 -99.0

142 23.2380036 30.5408871 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.467 1.858 0.76 0.001 -99.0 -99.0

143 23.3351058 30.5480067 0.16 1.257 0.06 1.493 3.59 1.726 3.51 1.283 4.55 0.001 9.62 1.985

144 23.4131379 30.6354521 0.245 1.131 0.57 1.02 1.519 1.131 3.996 1.327 33.199 1.682 71.21 1.508

145 23.2365346 30.5483727 0.51 1.229 0.49 1.106 1.13 1.16 -99.0 -99.0 2.56 0.028 8.238 0.801

146 23.3896177 30.5597423 -99.0 -99.0 -99.0 -99.0 3.13 2.283 2.16 0.405 3.71 0.001 94.63 1.289

147 23.6815822 30.5475032 0.019 0.262 0.014 0.666 0.112 0.448 0.28 0.381 2.22 0.001 -99.0 -99.0

148 23.660053 30.5477418 -99.0 -99.0 0.022 0.855 0.146 0.78 0.24 0.765 0.71 0.0 1.08 0.282

149 23.5934988 30.5555251 0.35 2.284 0.19 2.347 -99.0 -99.0 1.38 2.444 5.08 0.001 10.614 0.836

150 23.5349968 30.5499343 -99.0 -99.0 0.075 0.888 0.388 1.102 1.327 1.09 1.883 0.863 -99.0 -99.0

151 23.7138106 30.5466412 -99.0 -99.0 -99.0 -99.0 0.11 0.609 0.69 0.723 0.3 0.001 0.563 1.32

152 23.3790765 30.55941 -99.0 -99.0 0.15 1.976 1.86 2.021 10.23 1.952 9.73 0.014 19.34 1.787

153 23.6028416 30.5518649 0.18 0.737 0.12 0.801 0.111 0.7 0.173 0.495 2.72 0.002 0.701 0.4

154 23.216564 30.5486997 -99.0 -99.0 -99.0 -99.0 0.207 0.634 0.26 0.966 0.21 0.191 -99.0 -99.0

155 23.2525742 30.5664134 -99.0 -99.0 -99.0 -99.0 5.27 1.867 22.98 1.005 12.75 0.618 109.91 1.795

156 23.4787314 30.5667815 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 7.9 1.938 -99.0 -99.0

157 23.2583902 30.5803033 1.79 1.774 0.35 1.622 3.36 2.692 41.51 1.56 24.69 0.453 32.504 0.664

158 23.3874995 30.5626085 0.958 2.659 1.213 2.681 1.234 2.615 1.087 2.398 3.595 0.406 11.577 1.594

159 23.3038175 30.5704297 0.52 0.946 0.51 0.783 1.07 0.826 1.908 0.629 7.58 0.128 -99.0 -99.0

160 23.2514615 30.5531872 0.16 0.757 0.22 0.701 0.26 0.707 0.39 0.695 0.57 0.001 0.726 0.49

161 23.2925744 30.554711 1.6 1.969 1.04 1.991 0.63 2.41 0.88 2.073 0.38 0.124 -99.0 -99.0

162 23.6074399 30.555159 0.05 0.752 0.1 0.451 0.219 0.591 0.31 0.351 0.38 0.001 -99.0 -99.0

163 23.2525361 30.5729212 1.26 2.459 -99.0 -99.0 1.039 1.077 2.977 1.039 13.33 0.429 13.304 1.826

164 23.7041713 30.5580431 0.19 0.532 0.23 0.416 0.22 0.385 0.29 0.622 0.55 0.0 -99.0 -99.0

165 23.4966018 30.5968722 9.53 1.065 6.8 1.018 24.41 1.07 24.015 0.747 89.879 0.041 59.847 0.813

166 23.4772433 30.5775154 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 12.26 0.011 7.657 1.866

167 23.6714293 30.5595353 0.014 0.541 0.015 0.573 0.144 0.799 0.32 0.922 0.47 0.001 0.075 0.599

168 23.3970484 30.6078945 7.15 0.111 4.01 0.35 6.802 0.84 19.633 0.828 17.062 1.374 60.9 1.895

169 23.3008364 30.5746583 0.15 0.97 0.067 1.242 1.284 1.296 3.218 1.223 4.63 0.352 -99.0 -99.0

170 23.6638671 30.5627627 0.15 0.638 0.15 0.618 -99.0 -99.0 0.86 0.513 0.34 0.001 -99.0 -99.0

171 23.6552803 30.5817449 0.68 0.929 0.55 0.829 2.86 1.088 11.94 1.018 59.38 0.003 18.96 1.197

172 23.425105 30.5730196 -99.0 -99.0 -99.0 -99.0 0.701 0.502 3.624 0.288 15.285 0.454 -99.0 -99.0

173 23.5763911 30.5756712 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.254 1.221 2.22 0.001 23.882 1.264

174 23.5456241 30.6048973 4.74 0.758 3.65 0.518 28.73 0.574 13.459 1.784 105.67 0.189 33.12 0.764

175 23.2466984 30.5796258 0.84 1.197 0.73 1.046 1.23 0.305 8.37 1.342 5.24 0.49 13.045 2.382

176 23.4222639 30.5715262 0.21 2.946 -99.0 -99.0 0.77 0.317 2.86 0.775 0.8 0.292 0.8 0.396

177 23.4678741 30.5759677 -99.0 -99.0 -99.0 -99.0 0.62 2.329 2.425 1.738 58.26 0.721 -99.0 -99.0

178 23.2181368 30.584627 0.24 1.853 0.14 2.035 1.85 0.451 6.66 0.973 8.74 0.56 46.81 2.917

179 23.3957336 30.5732324 0.062 2.789 0.053 0.667 0.2 0.592 0.557 0.413 0.91 0.061 -99.0 -99.0

180 23.3483409 30.5743059 0.28 0.881 0.31 0.659 0.188 0.463 0.67 0.402 1.66 0.038 -99.0 -99.0

181 23.2877777 30.5827724 0.19 2.588 0.13 2.173 0.82 2.023 4.12 2.096 3.74 1.764 -99.0 -99.0

182 23.3859728 30.6155237 0.81 1.825 1.64 1.776 10.11 1.326 4.592 0.667 35.84 0.064 9.0 0.433

183 23.2423017 30.5802227 -99.0 -99.0 -99.0 -99.0 0.215 1.322 0.704 1.471 11.369 1.11 -99.0 -99.0

184 23.3909423 30.6915587 24.63 2.767 23.3 2.096 -99.0 -99.0 -99.0 -99.0 1434.67 0.929 -99.0 -99.0

185 23.4390916 30.6136023 4.74 0.545 3.22 1.017 23.3 0.646 30.405 0.622 136.49 0.047 24.692 0.546

186 23.274171 30.5832355 0.019 2.686 -99.0 -99.0 0.92 2.668 1.651 2.699 1.76 0.022 -99.0 -99.0

187 23.5647071 30.6200833 2.92 0.863 2.67 1.006 7.34 2.571 4.592 2.638 216.15 0.426 63.908 0.404

188 23.6333844 30.5817639 0.19 0.374 0.22 0.308 0.24 0.553 0.48 0.295 1.16 0.052 -99.0 -99.0

189 23.3151417 30.5847772 0.55 1.589 0.52 1.067 1.41 0.813 1.948 1.513 2.4 0.264 0.101 1.19

190 23.2808383 30.587491 -99.0 -99.0 -99.0 -99.0 1.65 2.953 3.556 2.474 2.97 0.022 1.965 1.134

191 23.404885 30.5862258 -99.0 -99.0 0.31 1.08 1.62 0.437 8.176 0.316 1.48 0.002 4.148 1.275

192 23.4580465 30.5838051 0.16 0.334 0.06 0.46 1.558 1.445 1.5 2.902 0.75 0.002 -99.0 -99.0

193 23.3949208 30.6182892 3.89 1.172 3.49 0.829 20.17 1.772 18.729 0.788 56.527 0.121 61.5 0.969

194 23.5957164 30.5871002 0.24 2.87 0.05 2.883 0.26 0.848 1.83 0.463 1.03 0.259 2.13 1.331

195 23.5453392 30.5978751 0.43 0.448 1.0 0.662 5.14 0.529 5.926 0.465 19.58 0.093 11.23 2.186

196 23.5929936 30.5886504 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.721 0.074 -99.0 -99.0

197 23.2319069 30.5933869 0.24 0.252 0.09 0.096 0.35 0.738 1.48 1.431 5.63 0.016 4.73 2.611

198 23.50982 30.6456077 64.19 1.915 -99.0 -99.0 -99.0 -99.0 239.2 2.931 258.82 2.863 67.405 0.8

199 23.4978759 30.599838 0.67 0.361 0.686 0.388 5.627 0.23 16.026 0.234 39.301 0.292 -99.0 -99.0

200 23.6299726 30.5893845 0.011 0.371 0.01 0.571 0.333 0.947 1.08 1.048 0.72 0.0 -99.0 -99.0

201 23.4588671 30.6248737 2.93 0.973 2.29 1.09 16.63 1.449 28.476 0.821 100.66 1.428 39.91 2.579

202 23.2861385 30.5906052 0.98 0.598 1.23 0.714 1.47 0.577 2.03 0.596 1.25 0.003 -99.0 -99.0

203 23.4793863 30.5914266 -99.0 -99.0 -99.0 -99.0 0.38 1.047 1.166 0.876 0.71 0.003 -99.0 -99.0

204 23.4017975 30.5921185 4.78 0.902 2.74 0.916 2.0 0.931 1.66 0.729 0.47 0.001 -99.0 -99.0

205 23.3237072 30.5951935 0.2 1.553 0.09 1.175 0.57 0.185 4.1 0.362 0.23 0.171 0.36 1.812

206 23.4515238 30.5964118 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.58 0.006 -99.0 -99.0

207 23.2377615 30.5997876 -99.0 -99.0 -99.0 -99.0 0.372 0.365 1.92 0.707 1.04 0.001 12.01 2.376

208 23.3562276 30.5978429 0.77 0.492 1.28 0.508 1.54 0.463 1.84 0.41 1.35 0.0 -99.0 -99.0

209 23.4639265 30.5974045 0.17 1.778 0.176 1.791 0.29 0.494 1.8 0.309 0.46 0.002 1.67 0.151

210 23.4319437 30.6509415 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 187.31 1.931 197.57 2.463

211 23.2292997 30.5976103 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.606 0.176 5.143 0.751

212 23.2416602 30.6017643 1.186 1.504 0.663 1.527 0.759 1.507 1.259 1.48 1.088 0.089 -99.0 -99.0

213 23.4722505 30.6015189 -99.0 -99.0 -99.0 -99.0 0.22 1.041 25.631 0.368 0.92 0.081 -99.0 -99.0

214 23.2332881 30.5998748 0.378 1.271 0.418 1.391 0.381 1.613 0.52 0.71 0.434 0.114 -99.0 -99.0

215 23.4775595 30.6015451 0.05 2.912 0.093 2.704 0.468 2.795 -99.0 -99.0 1.091 0.038 -99.0 -99.0

216 23.4666875 30.611183 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 4.09 0.004 6.49 0.743

217 23.3404764 30.6065863 0.85 0.669 0.99 0.742 1.52 0.525 2.85 0.63 3.99 0.015 -99.0 -99.0

218 23.2833369 30.6042448 -99.0 -99.0 -99.0 -99.0 0.066 0.28 0.509 2.497 0.21 0.002 -99.0 -99.0

219 23.5263608 30.6283346 -99.0 -99.0 -99.0 -99.0 7.22 1.61 -99.0 -99.0 12.92 0.827 -99.0 -99.0

220 23.6274042 30.6098987 0.33 1.747 0.192 0.525 0.47 0.639 1.49 0.785 2.16 0.001 0.252 0.225

221 23.3639789 30.6081481 0.17 1.616 0.105 2.48 0.3 0.595 2.415 0.544 0.75 0.002 0.047 2.58

222 23.5300461 30.60892 0.43 1.354 0.12 2.643 1.849 0.813 2.59 1.838 0.99 0.003 7.11 1.103

223 23.4475332 30.6187409 -99.0 -99.0 -99.0 -99.0 3.11 0.555 3.388 2.834 5.22 0.003 0.967 1.79

224 23.3134189 30.6111006 0.16 2.218 -99.0 -99.0 0.78 0.779 12.37 1.73 1.15 0.0 0.161 0.419

225 23.3702028 30.6733838 4.117 0.621 4.589 0.608 36.54 1.197 65.556 0.527 633.39 0.017 158.22 2.251

226 23.50066 30.6797439 4.39 0.682 5.146 0.663 26.189 0.641 76.676 0.479 1000.35 0.274 18.689 0.531

227 23.498594 30.6198509 1.11 2.732 -99.0 -99.0 7.61 2.254 -99.0 -99.0 7.28 0.004 -99.0 -99.0

228 23.2437321 30.6103843 0.09 0.502 0.03 0.437 0.54 0.516 3.48 0.623 0.97 0.001 1.09 0.93

229 23.5626519 30.6269113 1.17 0.742 2.05 0.488 10.17 0.908 7.407 0.734 21.243 0.038 -99.0 -99.0

230 23.5074748 30.6226856 -99.0 -99.0 0.23 2.296 3.17 2.106 -99.0 -99.0 6.56 0.001 9.177 1.012

231 23.306399 30.6582237 0.84 0.928 0.66 1.451 8.71 1.534 7.003 1.096 34.39 0.035 3.433 0.507

232 23.3802176 30.6340207 0.45 1.462 0.27 1.313 11.15 0.514 2.329 0.944 27.57 0.007 22.82 1.972

233 23.2292626 30.61458 0.52 1.111 0.34 0.844 0.26 0.847 1.26 1.02 0.74 0.002 3.815 2.972

234 23.3977557 30.6581247 4.06 0.501 3.11 0.338 9.788 0.678 27.048 0.422 194.41 0.081 18.056 0.777

235 23.5122553 30.6286521 0.91 2.567 0.7 1.64 4.26 0.763 7.66 1.218 5.76 0.002 11.722 2.571

236 23.2987395 30.6491089 1.69 0.713 1.208 1.39 9.21 1.068 31.79 1.332 27.994 0.161 41.971 0.319

237 23.7037368 30.6246831 -99.0 -99.0 -99.0 -99.0 0.18 2.776 0.86 2.633 3.19 0.379 0.43 1.646

238 23.1891098 30.648771 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 61.68 1.53 368.95 1.037

239 23.4483822 30.6444345 0.669 2.756 0.606 2.751 6.135 2.951 16.634 2.544 82.36 0.453 124.33 0.148

240 23.5373803 30.6525042 -99.0 -99.0 1.23 0.464 8.07 0.492 24.91 1.143 81.69 0.036 -99.0 -99.0

241 23.2781665 30.6289551 0.06 1.39 0.055 1.33 0.33 1.478 2.07 1.113 4.33 0.023 -99.0 -99.0

242 23.5853333 30.6329828 0.18 1.909 0.035 1.001 -99.0 -99.0 14.94 0.506 4.89 0.001 20.11 1.336

243 23.5361604 30.6274222 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 6.712 1.728 1.38 0.003 -99.0 -99.0

244 23.6966122 30.6321576 0.3 0.355 0.17 0.446 1.23 0.477 5.31 0.658 5.09 0.069 4.57 0.366

245 23.2178479 30.6211361 0.08 1.645 -99.0 -99.0 0.206 0.851 0.66 0.661 0.18 0.001 1.34 0.353

246 23.5156327 30.6313122 1.251 0.883 1.145 0.816 0.907 0.814 0.818 0.821 1.562 0.084 -99.0 -99.0

247 23.5022229 30.6357354 -99.0 -99.0 -99.0 -99.0 9.34 1.734 31.27 1.492 8.899 0.061 17.95 0.153

248 23.4862749 30.6250972 0.57 1.484 0.46 1.412 1.277 1.475 4.051 2.724 1.304 0.441 -99.0 -99.0

249 23.3670659 30.6257606 0.15 2.989 0.1 2.719 -99.0 -99.0 -99.0 -99.0 0.39 0.003 0.055 1.631

250 23.5408285 30.6375233 1.01 0.862 1.5 0.802 3.05 0.799 8.87 0.26 11.76 0.01 0.2 0.412

251 23.3032423 30.6451688 3.86 2.367 3.09 2.304 2.518 1.353 17.14 2.974 35.19 0.261 14.732 0.688

252 23.3588787 30.6304911 -99.0 -99.0 -99.0 -99.0 5.559 1.418 1.611 2.255 0.74 0.073 -99.0 -99.0

253 23.3605019 30.6506041 2.03 2.931 -99.0 -99.0 -99.0 -99.0 0.727 1.155 17.68 0.564 6.937 1.766

254 23.3648166 30.6287867 -99.0 -99.0 -99.0 -99.0 1.039 0.337 2.472 0.719 1.276 0.147 -99.0 -99.0

255 23.6939075 30.637165 0.31 0.577 0.12 0.684 1.28 0.681 2.748 0.072 2.226 0.126 4.922 0.723

256 23.455278 30.6333584 -99.0 -99.0 0.32 0.549 1.45 1.161 4.75 0.753 4.55 0.019 -99.0 -99.0

257 23.3618237 30.6449707 1.34 1.011 0.64 0.771 2.126 0.487 6.18 0.2 17.28 0.38 13.11 1.429

258 23.5539412 30.6350589 0.45 0.841 0.83 0.636 1.2 0.544 1.09 0.546 1.39 0.046 -99.0 -99.0

259 23.5738589 30.634089 0.5 1.565 0.22 1.541 -99.0 -99.0 -99.0 -99.0 0.59 0.003 -99.0 -99.0

260 23.2934401 30.6466653 0.46 0.329 0.73 0.235 0.87 0.306 2.45 0.463 11.18 0.055 -99.0 -99.0

261 23.5768249 30.6354645 1.881 1.239 1.08 1.183 0.947 1.147 0.983 1.166 0.487 0.255 -99.0 -99.0

262 23.3230689 30.6363488 0.28 0.687 0.23 0.625 0.206 0.759 0.94 0.715 1.31 0.001 -99.0 -99.0

263 23.2229493 30.6375472 0.289 0.495 0.346 0.568 0.423 0.645 -99.0 -99.0 2.639 1.203 -99.0 -99.0

264 23.2215632 30.6358148 0.23 0.291 0.27 0.267 -99.0 -99.0 0.4 0.262 0.79 0.181 -99.0 -99.0

265 23.6530394 30.6374993 -99.0 -99.0 -99.0 -99.0 0.112 2.684 -99.0 -99.0 1.0 0.071 1.01 2.789

266 23.5325477 30.653787 0.343 0.392 0.339 0.217 2.436 0.274 6.768 0.151 14.889 0.147 -99.0 -99.0

267 23.4320263 30.6833536 55.4 2.729 3.25 2.228 41.51 1.861 7.808 1.384 46.14 0.145 13.007 1.355

268 23.3737535 30.6429053 -99.0 -99.0 0.033 1.193 0.44 1.176 5.924 0.886 0.95 0.063 -99.0 -99.0

269 23.4835742 30.6530796 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.722 2.778 4.2 0.011 -99.0 -99.0

270 23.3420438 30.6461182 0.41 0.257 0.82 0.826 1.69 0.984 3.53 0.985 1.91 0.003 -99.0 -99.0

271 23.5435613 30.6544413 -99.0 -99.0 0.143 0.909 6.21 2.38 9.295 2.452 9.04 0.115 11.267 0.185

272 23.3503725 30.6532 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 2.279 2.06 0.46 1.056 -99.0 -99.0

273 23.407445 30.6596327 0.274 0.567 0.23 0.562 2.401 0.863 6.703 0.499 6.978 0.039 3.566 0.279

274 23.3403854 30.6495644 0.673 0.431 0.556 0.36 0.708 0.383 2.172 0.565 2.416 0.204 -99.0 -99.0

275 23.4880319 30.6493804 -99.0 -99.0 -99.0 -99.0 1.51 0.433 4.166 1.053 0.99 0.121 -99.0 -99.0

276 23.4900755 30.7053428 1.925 0.568 3.88 1.248 25.06 1.298 37.937 0.372 95.97 0.085 90.55 1.81

277 23.6492502 30.6738673 0.39 1.872 -99.0 -99.0 4.22 0.621 3.133 1.089 15.21 1.223 0.361 0.694

278 23.2647003 30.6511552 0.27 0.52 0.37 0.57 0.54 0.617 0.81 0.746 1.91 0.035 -99.0 -99.0

279 23.3465799 30.6508679 -99.0 -99.0 -99.0 -99.0 1.19 0.556 3.961 0.768 1.1 0.191 -99.0 -99.0

280 23.4057678 30.6574906 0.61 2.36 0.3 1.523 1.63 0.848 -99.0 -99.0 10.303 0.973 -99.0 -99.0

281 23.6559155 30.670175 -99.0 -99.0 0.024 0.665 0.075 1.281 -99.0 -99.0 1.94 0.362 0.084 0.677

282 23.3305157 30.6582338 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 9.32 1.776 2.16 0.049 6.594 2.247

283 23.4265111 30.6685087 -99.0 -99.0 -99.0 -99.0 4.62 2.732 -99.0 -99.0 6.24 0.001 -99.0 -99.0

284 23.2787484 30.6528663 0.2 0.405 0.13 0.251 0.232 0.62 0.235 0.639 0.88 0.001 -99.0 -99.0

285 23.4972031 30.6574364 0.131 2.03 0.108 1.824 1.02 0.872 6.824 0.445 0.95 0.003 -99.0 -99.0

286 23.422845 30.6964213 0.622 2.564 2.4 0.952 -99.0 -99.0 -99.0 -99.0 104.03 1.32 155.37 1.731

287 23.5542603 30.7003956 0.56 2.609 0.37 2.637 -99.0 -99.0 99.52 2.491 36.19 0.252 5.406 2.558

288 23.5534039 30.6712449 0.5 2.402 0.6 2.409 -99.0 -99.0 -99.0 -99.0 5.65 0.014 8.56 1.102

289 23.6025439 30.6626101 0.39 2.229 0.1 2.093 0.59 1.855 -99.0 -99.0 2.98 0.039 -99.0 -99.0

290 23.2648052 30.6650077 0.1 2.258 0.08 1.927 1.71 1.624 5.44 0.763 4.33 0.021 7.953 2.37

291 23.2309423 30.6592021 0.22 1.376 0.05 1.053 0.23 0.728 1.88 1.509 1.08 0.001 3.93 0.897

292 23.4857212 30.6837624 1.737 0.977 0.991 0.564 12.07 0.049 13.102 0.571 8.785 0.274 12.81 0.048

293 23.6956205 30.6601853 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.056 1.867 0.772 0.03 -99.0 -99.0

294 23.1957872 30.66283 0.06 1.57 0.111 0.932 0.179 0.517 0.35 0.569 1.82 0.037 -99.0 -99.0

295 23.4160083 30.6686131 -99.0 -99.0 -99.0 -99.0 1.03 2.184 -99.0 -99.0 3.21 0.003 1.44 1.868

296 23.2580642 30.6641098 1.31 2.836 -99.0 -99.0 1.45 1.125 4.43 1.691 2.76 0.254 0.4 2.236

297 23.4612661 30.6889857 15.6 1.695 -99.0 -99.0 4.373 0.343 13.748 0.481 21.454 0.342 -99.0 -99.0

298 23.5288203 30.6961545 1.91 2.232 1.41 1.704 27.88 2.015 -99.0 -99.0 79.67 1.85 152.0 2.093

299 23.3258953 30.6893883 0.42 1.429 0.15 0.614 0.997 0.477 3.215 0.65 13.92 0.022 9.43 1.883

300 23.4075672 30.6798624 -99.0 -99.0 -99.0 -99.0 2.49 1.851 66.526 0.536 4.41 0.001 -99.0 -99.0

301 23.6259803 30.6768091 1.99 2.837 1.26 2.575 1.49 2.158 2.84 1.416 4.09 0.025 22.33 1.521

302 23.3743258 30.6801545 0.558 0.672 0.71 1.07 2.977 0.95 7.792 0.67 26.316 0.026 24.407 0.903

303 23.3199767 30.6738485 0.1 1.637 0.09 0.834 0.23 0.495 0.823 0.726 1.49 0.053 -99.0 -99.0

304 23.6790852 30.6756613 0.13 1.23 0.08 0.907 0.48 0.602 1.98 0.434 1.75 0.239 -99.0 -99.0

305 23.4159351 30.6854883 1.33 1.163 0.96 1.228 4.08 0.893 10.516 0.558 16.973 0.11 24.33 1.116

306 23.6778627 30.6804357 -99.0 -99.0 0.021 0.541 0.225 0.505 0.574 0.518 2.417 0.036 -99.0 -99.0

307 23.3278438 30.6767446 0.06 2.453 0.121 2.202 1.41 0.853 3.408 0.829 1.26 0.0 -99.0 -99.0

308 23.1794239 30.676677 0.05 0.695 0.096 0.396 0.15 0.613 1.73 0.853 1.01 0.129 4.74 1.418

309 23.5742394 30.6763032 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.67 0.004 0.03 2.943

310 23.1765675 30.6772942 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.346 1.003 -99.0 -99.0

311 23.3965969 30.6775016 0.13 1.057 0.38 1.017 0.63 1.198 1.17 0.749 0.77 0.066 -99.0 -99.0

312 23.6407516 30.6849669 0.37 1.025 0.27 0.963 1.65 0.948 3.21 0.972 7.06 0.029 3.23 0.946

313 23.4473536 30.688507 0.135 2.195 0.52 2.115 2.25 2.463 1.595 2.688 3.83 2.687 -99.0 -99.0

314 23.2617399 30.6859556 0.15 1.885 0.244 2.032 0.91 1.319 3.16 1.468 2.054 1.499 7.229 0.812

315 23.7281912 30.6883464 -99.0 -99.0 -99.0 -99.0 0.204 0.831 0.84 0.886 1.4 0.108 4.323 0.012

316 23.6269102 30.6896408 -99.0 -99.0 0.3 2.926 1.96 1.639 10.1 1.395 7.72 0.001 11.32 2.609

317 23.2460603 30.6929722 3.99 0.666 2.46 0.69 4.21 0.243 19.5 0.81 12.61 0.0 1.56 2.593

318 23.2774538 30.6813692 0.057 1.844 0.04 1.479 0.051 0.155 0.199 0.445 0.53 0.001 -99.0 -99.0

319 23.5451985 30.7056543 0.61 0.451 0.441 0.227 1.693 1.065 4.618 1.032 3.664 0.673 13.348 0.68

320 23.2564197 30.6849835 0.24 2.359 0.06 2.329 0.332 0.52 1.01 0.648 0.83 0.075 0.6 1.454

321 23.4181752 30.7654054 -99.0 -99.0 3.12 2.713 44.27 1.022 19.962 2.945 101.03 0.004 34.22 1.035

322 23.5696987 30.6886576 0.69 0.393 0.46 0.479 0.32 0.435 1.854 0.385 1.26 0.001 -99.0 -99.0

323 23.5191676 30.6870017 -99.0 -99.0 -99.0 -99.0 1.63 1.435 3.47 0.538 1.44 0.004 1.03 0.695

324 23.3100024 30.7547369 0.79 0.721 0.59 1.019 4.867 0.963 2.831 0.448 60.17 0.513 -99.0 -99.0

325 23.4830367 30.7221122 0.76 0.521 0.51 0.6 5.98 0.582 29.56 2.521 7.342 0.299 5.1 0.262

326 23.5563729 30.6925001 0.033 1.403 0.05 1.542 0.097 0.815 8.933 2.896 0.66 0.004 0.234 0.635

327 23.2018147 30.692144 -99.0 -99.0 0.023 0.489 0.296 0.616 0.49 0.671 0.8 0.001 0.137 0.39

328 23.191209 30.6932802 0.12 0.973 0.08 0.855 0.13 0.762 0.85 0.733 1.05 0.001 4.6 0.153

329 23.4626802 30.6976633 0.19 0.924 0.16 0.515 0.33 0.531 0.86 0.448 0.6 0.002 -99.0 -99.0

330 23.3636271 30.6999567 0.56 1.614 0.21 1.272 0.36 0.965 1.33 0.648 1.58 0.001 -99.0 -99.0

331 23.1789114 30.7000799 0.042 0.893 0.014 0.805 0.13 0.591 0.17 0.844 0.4 0.003 -99.0 -99.0

332 23.6862291 30.7104179 -99.0 -99.0 -99.0 -99.0 1.2 2.672 6.733 1.425 3.618 0.08 3.515 0.998

333 23.4186642 30.7178943 -99.0 -99.0 -99.0 -99.0 4.1 1.536 -99.0 -99.0 8.48 0.002 -99.0 -99.0

334 23.2837586 30.7067748 0.36 1.598 0.18 1.471 0.914 0.077 2.361 0.237 1.324 0.065 1.33 0.557

335 23.4353561 30.7437675 3.35 0.886 3.24 0.948 9.098 0.892 22.493 0.855 204.66 0.024 89.796 1.054

336 23.4823506 30.7140345 0.164 0.783 0.22 1.283 1.15 0.746 4.54 0.767 2.396 0.09 0.612 0.273

337 23.3705591 30.7047161 0.83 1.637 0.44 1.499 0.85 0.428 1.736 0.04 0.82 0.002 6.888 0.447

338 23.4410897 30.7128436 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 11.37 2.857 6.81 0.002 25.84 1.447

339 23.6892886 30.7068735 0.17 1.396 0.09 0.948 0.55 0.926 3.54 0.721 1.63 0.069 4.47 0.643

340 23.4813787 30.7577943 8.91 1.926 6.97 1.9 -99.0 -99.0 -99.0 -99.0 200.59 0.007 263.49 1.844

341 23.3779287 30.7073905 0.27 2.296 0.12 2.193 0.373 0.507 7.83 1.777 0.82 0.002 -99.0 -99.0

342 23.5046251 30.7315513 2.66 1.016 1.84 1.07 13.81 0.602 50.43 0.789 58.93 0.006 35.11 0.376

343 23.3284211 30.7127914 0.302 0.827 0.56 1.439 0.53 0.953 0.53 0.715 0.829 0.031 -99.0 -99.0

344 23.6847832 30.72261 0.18 0.335 0.031 0.496 0.444 0.251 1.82 0.158 3.46 0.006 1.75 2.513

345 23.4427305 30.7350593 1.92 2.677 1.42 0.641 6.53 1.924 20.49 1.623 21.62 0.409 -99.0 -99.0

346 23.2005507 30.7141313 0.27 0.769 0.14 0.762 0.143 0.349 0.104 0.788 0.21 0.001 -99.0 -99.0

347 23.3068917 30.7208665 0.07 0.748 0.072 0.801 0.45 0.973 2.14 1.127 2.71 0.029 0.764 0.755

348 23.2963855 30.7545119 2.96 0.201 2.964 0.404 21.28 0.789 72.63 0.832 177.96 0.11 196.41 0.792

349 23.588217 30.7268656 -99.0 -99.0 -99.0 -99.0 0.88 0.734 2.816 0.357 1.751 0.077 2.063 0.488

350 23.5853593 30.7249357 0.25 2.342 0.12 2.401 0.193 1.779 1.25 0.736 0.77 0.111 -99.0 -99.0

351 23.5722855 30.7303298 0.07 1.498 0.03 1.702 0.97 1.087 9.85 1.218 1.78 0.043 0.759 1.157

352 23.6159013 30.7278468 1.36 0.471 1.86 0.435 2.1 0.446 2.23 0.281 2.34 0.001 -99.0 -99.0

353 23.3367059 30.7268656 0.32 0.766 0.24 0.746 0.225 0.69 0.51 0.505 1.34 0.002 0.053 1.389

354 23.3398438 30.7280363 -99.0 -99.0 0.128 0.745 0.096 0.944 0.212 0.553 0.759 0.08 -99.0 -99.0

355 23.4290995 30.744778 2.63 1.304 1.95 1.101 7.748 1.563 23.673 1.903 49.43 0.048 38.495 0.366

356 23.5378834 30.7326145 0.2 0.465 0.335 0.474 0.8 0.517 1.37 0.383 2.66 0.02 -99.0 -99.0

357 23.5755386 30.7323384 -99.0 -99.0 0.034 0.303 0.897 1.137 2.695 0.639 0.562 0.081 -99.0 -99.0

358 23.712761 30.7324576 0.107 0.109 0.14 0.191 0.176 0.249 0.189 0.346 0.34 0.002 -99.0 -99.0

359 23.5783413 30.7355878 -99.0 -99.0 -99.0 -99.0 1.011 0.555 2.647 0.132 1.541 0.194 4.291 2.661

360 23.5028228 30.7421674 0.91 2.044 0.63 1.276 3.4 1.054 24.96 1.629 3.48 0.011 3.17 2.587

361 23.5066628 30.7488883 0.44 1.03 0.29 0.863 1.374 0.577 3.813 0.991 17.99 0.001 8.225 0.92

362 23.5556356 30.7450627 0.29 2.333 0.04 2.904 2.31 2.153 4.551 1.222 4.08 0.002 -99.0 -99.0

363 23.2441858 30.7422111 0.1 0.45 0.07 0.427 0.44 0.168 1.87 1.068 2.01 0.001 4.352 1.053

364 23.2183934 30.7403776 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.31 2.51 1.319 0.027 0.072 1.576

365 23.5405183 30.7389008 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.887 1.114 0.58 0.147 -99.0 -99.0

366 23.3949093 30.7454522 -99.0 -99.0 -99.0 -99.0 0.96 0.248 2.885 0.444 1.67 0.092 -99.0 -99.0

367 23.5446783 30.7487836 -99.0 -99.0 -99.0 -99.0 1.22 2.576 14.61 1.22 3.61 0.002 0.231 1.18

368 23.5526339 30.752373 -99.0 -99.0 -99.0 -99.0 1.64 1.793 9.16 0.878 2.61 0.044 7.821 0.745

369 23.5542291 30.7589305 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 4.463 2.273 9.31 0.181 -99.0 -99.0

370 23.2488596 30.7455636 -99.0 -99.0 -99.0 -99.0 0.135 0.596 0.316 1.048 0.39 0.001 -99.0 -99.0

371 23.266285 30.7481966 0.21 1.412 0.15 1.193 0.103 0.468 0.25 0.639 1.3 0.001 -99.0 -99.0

372 23.1921287 30.7461989 -99.0 -99.0 -99.0 -99.0 0.434 0.81 0.939 0.201 0.21 0.174 2.75 0.775

373 23.3634157 30.7510251 0.31 2.741 -99.0 -99.0 0.99 0.882 7.24 1.412 1.19 0.15 0.92 0.47

374 23.4470914 30.758189 -99.0 -99.0 -99.0 -99.0 5.97 2.357 33.36 2.188 6.95 0.028 -99.0 -99.0

375 23.2843986 30.7525087 0.11 1.955 0.027 0.142 0.26 0.391 0.6 0.328 0.77 0.001 0.243 0.824

376 23.2399159 30.7517994 -99.0 -99.0 -99.0 -99.0 0.045 0.542 0.113 0.434 0.34 0.001 -99.0 -99.0

377 23.2780267 30.7565926 -99.0 -99.0 -99.0 -99.0 0.561 1.311 -99.0 -99.0 0.76 0.005 -99.0 -99.0

378 23.6687258 30.7656076 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 3.8 1.629 7.49 0.001 1.53 0.47

379 23.3184471 30.7858609 0.59 1.068 0.3 1.059 3.05 0.919 2.796 1.254 9.91 1.357 4.992 0.499

380 23.2144993 30.7601547 -99.0 -99.0 -99.0 -99.0 0.033 0.888 0.077 0.542 0.54 0.001 0.442 2.745

381 23.4686411 30.7740396 0.32 1.351 0.36 0.58 2.57 1.061 21.45 1.999 7.82 0.002 5.64 2.665

382 23.280334 30.7619284 3.13 0.478 2.75 0.582 2.4 0.534 2.8 0.462 0.56 0.003 -99.0 -99.0

383 23.6238238 30.7650439 0.76 0.542 0.99 0.644 1.04 0.621 0.99 0.62 1.29 0.046 -99.0 -99.0

384 23.2076778 30.7654054 0.048 0.28 0.039 0.297 0.258 0.297 0.49 0.526 0.28 0.0 0.746 0.123

385 23.4941868 30.7732033 0.16 1.24 0.07 0.962 0.88 0.678 2.213 0.801 2.325 0.063 0.221 0.417

386 23.5321648 30.7702218 0.87 2.541 0.39 2.157 0.47 1.253 2.66 1.63 0.93 0.005 1.121 3.0

387 23.3923703 30.7910931 0.156 0.495 0.114 0.406 1.069 0.288 3.232 0.521 1.805 0.683 0.982 0.232

388 23.5520915 30.9057374 0.479 0.529 1.04 0.54 1.78 0.465 2.16 0.499 2.37 0.001 -99.0 -99.0

389 23.3708825 30.8078404 -99.0 -99.0 -99.0 -99.0 0.38 0.869 1.37 1.661 0.39 0.001 0.19 1.104

390 23.4955476 30.9254162 0.19 0.637 0.14 0.559 0.71 0.645 2.32 0.641 12.55 0.0 5.44 0.429

391 23.3663994 30.7953633 2.52 2.441 1.48 2.549 4.37 0.613 14.52 0.185 7.32 0.024 19.03 2.428

392 23.5688082 30.8649504 8.77 1.527 7.0 1.287 7.721 0.591 18.912 0.267 224.65 0.15 214.1 0.874

393 23.3814602 30.7914239 -99.0 -99.0 -99.0 -99.0 0.48 1.192 5.98 2.189 0.51 0.002 0.552 0.597

394 23.2177947 30.8619643 0.032 0.507 0.043 0.43 0.104 0.804 0.204 0.305 0.3 0.0 0.038 0.166

395 23.3784711 30.8173116 1.42 0.538 1.27 0.618 0.9 0.858 1.32 0.934 0.45 0.003 -99.0 -99.0

396 23.51218 30.8572721 0.5 2.392 0.13 0.738 1.57 0.313 13.36 1.906 7.46 0.007 50.09 0.349

397 23.4574031 30.8614626 0.118 2.448 0.161 1.895 0.15 0.764 1.75 1.148 1.13 0.052 11.474 0.803

398 23.5458523 30.8079254 0.11 2.147 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 15.57 0.848 -99.0 -99.0

399 23.6715006 30.8513604 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.75 0.001 -99.0 -99.0

400 23.5263124 30.8606255 -99.0 -99.0 0.09 2.719 1.646 1.588 3.841 0.876 5.19 0.033 8.74 2.26

401 23.4338307 30.8099453 0.42 0.377 0.22 0.316 1.81 0.49 4.591 0.373 4.91 0.02 3.16 0.142

402 23.55695 30.7896318 0.54 2.435 0.11 1.751 2.128 0.767 4.974 1.253 7.48 0.144 3.002 0.59

403 23.4949754 30.7908804 0.23 1.15 0.12 1.155 0.89 1.118 2.897 1.125 2.13 0.173 0.79 1.676

404 23.3089648 30.8568698 0.08 0.558 0.1 0.515 0.33 0.578 1.22 0.534 2.79 0.033 -99.0 -99.0

405 23.3987872 30.8482912 0.418 1.341 0.334 0.872 1.296 0.526 3.325 0.286 5.256 0.048 16.669 1.013

406 23.6087753 30.8166817 0.86 1.861 0.51 2.174 2.82 0.27 4.091 0.143 7.4 0.452 1.228 0.251

407 23.548629 30.8132312 0.1 1.895 0.066 2.115 -99.0 -99.0 -99.0 -99.0 2.85 0.179 -99.0 -99.0

408 23.3052668 30.8426466 0.34 1.057 0.23 0.655 1.94 0.651 7.54 1.407 6.27 0.017 13.91 0.292

409 23.3952365 30.8370405 0.24 0.936 0.13 1.057 -99.0 -99.0 3.34 2.97 9.0 0.015 11.1 2.414

410 23.4613394 30.7949125 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 1.59 0.003 -99.0 -99.0

411 23.4249291 30.7931596 0.93 0.691 0.58 0.628 5.52 0.686 5.086 1.031 15.48 0.132 5.864 0.312

412 23.4949753 30.8346301 0.36 0.562 0.32 0.516 0.22 0.482 1.84 0.785 1.84 0.001 0.314 2.053

413 23.3014687 30.821464 0.14 1.16 -99.0 -99.0 0.36 1.139 4.62 1.768 7.36 0.019 -99.0 -99.0

414 23.2957009 30.8095165 0.12 0.296 0.08 0.152 0.98 0.77 2.433 1.539 11.43 0.744 -99.0 -99.0

415 23.4019926 30.8439406 0.5 1.349 0.39 1.127 1.06 1.506 4.41 1.54 7.596 0.084 60.62 1.284

416 23.4841595 30.8511127 0.21 1.516 0.129 0.961 0.31 1.15 0.913 1.057 0.34 0.002 0.265 0.582

417 23.366927 30.8427976 0.054 1.423 0.063 1.383 0.087 0.883 0.267 0.669 0.75 0.001 -99.0 -99.0

418 23.2181081 30.8384177 0.24 1.441 0.17 0.961 0.56 0.534 1.58 0.643 7.24 0.033 1.57 0.729

419 23.4492321 30.8466044 0.52 0.091 0.34 0.399 1.01 2.326 -99.0 -99.0 4.96 0.042 31.62 2.827

420 23.5210173 30.8166038 -99.0 -99.0 -99.0 -99.0 1.14 1.911 4.995 0.037 3.34 0.129 -99.0 -99.0

421 23.1812805 30.8018275 -99.0 -99.0 0.06 1.459 0.16 1.266 0.57 1.309 3.93 0.033 0.73 2.044

422 23.4907269 30.7770533 -99.0 -99.0 -99.0 -99.0 2.286 1.997 7.231 2.274 1.236 0.37 2.971 1.111

423 23.4144609 30.7759326 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 0.64 0.001 -99.0 -99.0

424 23.6280097 30.8284288 -99.0 -99.0 -99.0 -99.0 0.33 0.524 1.41 0.894 1.288 0.01 0.37 0.124

425 23.3474003 30.8284719 0.134 1.964 0.099 1.606 0.434 0.921 0.944 0.896 3.049 0.073 0.356 0.475

426 23.4941016 30.8115477 1.637 0.432 1.98 0.432 5.577 0.661 80.06 1.543 82.0 0.115 9.615 0.505

427 23.495441 30.8197853 0.757 0.506 0.666 0.611 3.374 0.857 25.98 1.503 8.038 0.127 9.771 0.463

428 23.3024284 30.8107841 0.15 0.722 -99.0 -99.0 0.14 0.798 0.29 0.727 1.636 0.097 15.502 1.531

429 23.4907454 30.8176074 3.08 1.941 2.23 2.174 13.87 1.668 11.191 0.559 19.19 0.185 11.016 0.295

430 23.4626141 30.8213831 -99.0 -99.0 0.088 0.45 0.146 0.787 0.168 0.628 1.197 0.029 -99.0 -99.0

431 23.4990198 30.8227204 0.343 0.789 0.277 0.807 2.236 0.853 5.924 1.021 5.058 0.004 -99.0 -99.0

432 23.4840875 30.824481 -99.0 -99.0 -99.0 -99.0 0.29 0.75 1.173 0.998 0.47 0.001 0.125 0.68

433 23.3483471 30.8253958 -99.0 -99.0 -99.0 -99.0 0.21 1.746 0.85 0.886 0.42 0.022 -99.0 -99.0

434 23.5411217 30.8183276 0.35 1.125 0.1 1.116 0.44 0.539 5.944 1.288 0.947 0.296 -99.0 -99.0

435 23.3099436 30.8251711 0.34 2.647 -99.0 -99.0 -99.0 -99.0 0.63 1.862 0.692 0.027 -99.0 -99.0

436 23.5914998 30.8111663 1.69 1.447 1.1 1.375 24.74 1.399 12.172 1.879 48.87 0.276 25.02 2.509

437 23.6151254 30.8208454 0.076 1.288 0.061 1.187 0.392 0.726 1.709 1.013 0.71 0.003 0.218 0.398

438 23.5599839 30.8089016 -99.0 -99.0 -99.0 -99.0 18.0 2.567 40.29 2.944 24.17 0.846 -99.0 -99.0

439 23.4603869 30.8169624 -99.0 -99.0 0.18 2.645 0.191 1.75 0.329 0.879 0.65 0.002 0.236 2.077

440 23.4016647 30.8116122 1.95 2.072 1.27 1.429 10.93 1.73 3.673 0.651 18.29 0.018 8.97 2.965

441 23.5137195 30.8859375 0.25 0.249 0.12 0.356 0.7 0.795 2.74 1.114 2.13 0.001 3.89 0.234

442 23.3191453 30.7913209 0.27 0.298 0.23 0.016 0.92 0.462 1.5 0.687 2.59 0.159 -99.0 -99.0

443 23.6645764 30.800065 -99.0 -99.0 0.03 0.296 0.23 0.284 0.72 0.355 1.789 0.089 -99.0 -99.0

444 23.5321019 30.8054253 0.45 2.045 0.38 2.109 0.75 1.232 1.485 0.887 1.0 0.003 -99.0 -99.0

445 23.6687348 30.8042817 -99.0 -99.0 -99.0 -99.0 1.271 2.227 0.82 1.426 0.98 0.25 6.706 0.584

446 23.4427185 30.8706901 0.23 0.447 0.18 0.466 0.95 0.665 3.18 0.59 6.94 0.024 5.24 0.255

447 23.5480965 31.0422525 -99.0 -99.0 -99.0 -99.0 0.073 0.709 0.224 0.287 0.3 0.001 -99.0 -99.0

448 23.4258971 30.7960688 0.216 1.368 0.178 1.406 1.129 0.932 2.912 0.933 4.284 0.124 -99.0 -99.0

449 23.4382839 30.7943784 -99.0 -99.0 -99.0 -99.0 1.08 2.703 -99.0 -99.0 6.97 0.059 -99.0 -99.0

450 23.5158707 30.9160971 0.6 1.767 0.37 1.863 1.72 1.426 17.05 1.468 7.72 0.053 27.429 1.73

451 23.3907915 30.7865325 0.19 1.068 0.11 0.819 0.99 0.653 8.51 0.686 2.94 0.002 14.83 1.579

452 23.5494827 30.785238 -99.0 -99.0 -99.0 -99.0 1.82 1.353 12.783 0.828 1.02 0.071 -99.0 -99.0

453 23.5188945 30.9070833 0.14 2.792 -99.0 -99.0 0.33 1.566 -99.0 -99.0 0.51 0.156 -99.0 -99.0

454 23.5956995 30.7820692 0.31 2.004 0.23 1.713 0.59 0.941 3.23 0.994 1.84 0.046 13.87 1.38

455 23.569164 30.7810313 0.19 2.3 0.06 2.924 10.95 0.431 1.855 0.913 6.25 0.231 -99.0 -99.0

456 23.4667165 30.7878456 0.44 2.537 0.37 2.611 0.63 1.829 3.26 1.916 1.441 0.019 8.69 0.34

457 23.5455554 30.7764174 -99.0 -99.0 0.86 2.951 1.59 1.489 12.02 1.761 6.62 0.019 8.298 0.105

458 23.5743777 30.8800705 0.16 0.118 0.07 0.479 0.63 0.553 4.65 0.582 4.377 0.026 0.9 0.275

459 23.4482496 30.9017202 -99.0 -99.0 -99.0 -99.0 0.25 1.414 2.12 1.185 0.52 0.002 2.63 1.226

460 23.3412458 30.7959015 0.38 2.063 0.3 1.901 2.34 2.148 -99.0 -99.0 6.75 0.021 11.23 1.242

461 23.5113866 30.8281243 0.47 2.435 0.14 0.677 0.086 0.472 2.55 2.504 1.29 0.055 0.253 2.035

462 23.5086251 30.8769465 0.21 0.566 0.1 0.485 0.27 0.476 2.84 0.514 0.69 0.081 -99.0 -99.0

463 23.3723671 30.8372253 0.499 0.765 0.287 1.38 0.09 1.641 1.84 1.135 0.42 0.116 0.8 1.02

464 23.6725383 30.786192 0.22 2.399 -99.0 -99.0 4.71 2.752 21.68 2.751 9.34 0.0 -99.0 -99.0

465 23.6007448 30.9138192 0.3 1.951 0.16 2.19 0.32 0.695 2.12 0.316 4.74 0.045 12.847 1.013

466 23.6532015 30.8682463 0.25 2.433 0.17 1.909 -99.0 -99.0 0.27 0.712 0.32 0.112 -99.0 -99.0

467 23.4657954 30.8688818 0.159 0.468 0.1 0.524 0.102 0.57 0.44 0.523 0.71 0.001 -99.0 -99.0

468 23.4579162 30.8824059 -99.0 -99.0 -99.0 -99.0 0.56 0.874 1.183 1.022 1.351 0.17 2.424 0.128

469 23.511233 30.8969572 0.28 1.414 0.17 1.425 0.13 0.558 0.977 0.64 1.15 0.001 0.044 2.637

470 23.2262503 30.8403702 0.04 1.501 0.047 1.448 0.242 1.217 0.83 0.583 1.84 0.002 6.447 1.539

471 23.5508254 30.8873415 1.84 0.428 1.17 0.51 0.86 0.559 0.73 0.564 0.48 0.085 -99.0 -99.0

472 23.5687729 30.8724925 0.69 2.845 0.255 0.602 2.77 0.832 6.56 0.745 36.11 0.031 -99.0 -99.0

473 23.6242498 30.9545948 1.68 2.537 0.87 2.502 6.21 1.865 42.24 0.942 67.42 0.064 92.56 1.218

474 23.5446277 31.054989 0.14 1.366 0.03 0.722 0.21 1.143 1.53 1.486 1.89 0.002 1.92 1.437

475 23.6807839 30.8024574 -99.0 -99.0 0.05 0.144 0.111 0.406 0.252 0.398 1.13 0.003 0.074 2.947

476 23.5889273 30.9065559 0.47 1.073 0.3 1.382 0.89 0.623 3.041 0.495 1.87 0.002 5.4 0.669

477 23.5140251 30.9686822 0.032 1.334 0.02 1.396 0.158 1.37 0.45 1.225 1.89 0.156 -99.0 -99.0

478 23.4321075 31.0353863 0.31 1.995 0.41 0.839 0.8 0.788 2.2 0.588 17.38 0.007 -99.0 -99.0

479 23.3184214 30.8807218 8.25 1.224 13.58 1.228 48.73 1.55 154.18 1.415 1848.38 0.0 161.77 1.006

480 23.4796581 30.9040231 0.08 2.531 0.074 1.812 0.277 0.42 0.966 0.08 0.85 0.066 0.58 1.259

481 23.549858 30.9756237 -99.0 -99.0 0.033 0.786 0.106 0.639 0.11 0.789 0.21 0.156 -99.0 -99.0

482 23.4542822 30.8570718 -99.0 -99.0 0.37 1.38 1.21 1.655 4.08 1.438 3.79 0.001 -99.0 -99.0

483 23.5129404 31.0331657 0.14 1.093 0.078 1.101 0.116 0.982 0.072 1.052 0.31 0.124 -99.0 -99.0

484 23.5609306 30.8959397 0.79 1.157 0.34 1.324 0.8 1.116 4.38 1.324 1.38 0.002 2.27 2.53

485 23.4593204 30.9719328 0.044 1.653 0.08 0.654 0.18 0.8 0.58 0.804 0.21 0.001 -99.0 -99.0

486 23.5148818 30.802739 -99.0 -99.0 0.48 2.696 4.99 0.859 3.182 0.985 7.92 0.023 -99.0 -99.0

487 23.5609434 30.7914915 0.251 0.868 0.268 0.89 0.317 0.985 0.334 1.118 4.875 2.229 -99.0 -99.0

488 23.6074669 30.9219251 1.56 0.319 1.93 0.377 2.26 0.377 2.99 0.429 2.6 0.001 -99.0 -99.0

489 23.5117669 31.0475477 0.13 0.457 0.11 0.753 0.097 0.691 0.276 0.804 0.64 0.002 -99.0 -99.0

490 23.6169793 30.9334413 0.2 1.737 0.25 0.881 0.52 1.391 1.85 1.083 7.33 0.018 -99.0 -99.0

491 23.5572718 31.0671411 0.08 0.263 0.09 0.662 0.21 0.269 1.03 0.619 2.36 0.033 2.45 0.303

492 23.5794776 30.8082864 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 55.84 0.072 -99.0 -99.0

493 23.3667182 31.0053067 0.154 0.308 0.123 0.762 0.407 1.346 0.78 1.141 1.06 0.001 6.898 0.054

494 23.3163336 30.9456245 1.18 1.565 1.53 1.243 -99.0 -99.0 -99.0 -99.0 46.92 0.005 56.046 0.362

495 23.4443025 30.8555902 0.98 1.781 0.65 2.335 0.54 2.765 1.07 1.708 0.74 0.001 1.09 1.571

496 23.6318909 30.9570706 0.71 0.891 0.65 0.764 1.446 0.521 3.469 0.395 5.024 0.091 -99.0 -99.0

497 23.5328498 31.0325562 0.027 0.123 0.06 0.874 0.191 0.794 0.17 0.754 1.32 0.001 -99.0 -99.0

498 23.4575392 30.878299 3.58 0.95 3.6 0.806 3.39 0.831 3.73 0.753 1.31 0.003 -99.0 -99.0

499 23.5926926 30.945429 0.53 0.597 0.32 0.548 0.09 0.103 1.51 0.483 0.36 0.001 -99.0 -99.0

500 23.340851 30.9226573 0.27 0.799 0.27 0.51 -99.0 -99.0 0.49 0.375 1.89 0.001 -99.0 -99.0

501 23.5026165 30.7913101 0.36 2.145 0.08 2.057 0.78 1.265 2.432 1.272 0.4 0.0 -99.0 -99.0

502 23.5112777 30.8120784 -99.0 -99.0 -99.0 -99.0 -99.0 -99.0 6.05 1.368 1.59 0.07 0.212 2.052

503 23.5105026 30.9696764 0.212 0.391 0.187 0.461 1.156 0.406 2.851 0.413 5.448 0.033 2.363 0.523

504 23.5110998 30.918498 0.14 1.977 0.187 0.721 0.393 0.594 1.308 1.555 1.168 0.124 -99.0 -99.0

505 23.3607924 30.9540566 0.54 0.76 0.58 0.831 0.43 0.81 0.8 0.801 1.75 0.002 0.56 2.891

506 23.4756051 30.9593013 0.012 0.911 0.023 0.845 0.179 0.842 0.36 0.622 0.2 0.147 -99.0 -99.0

507 23.5273085 30.815905 0.48 1.315 0.29 1.214 1.42 1.729 5.51 1.819 8.93 0.194 31.03 1.072

508 23.561598 30.9585245 0.35 0.9 0.26 0.881 0.284 0.739 0.75 0.859 0.34 0.001 -99.0 -99.0

509 23.4573301 30.942474 0.08 0.852 0.1 0.865 0.188 1.013 0.23 0.779 0.51 0.089 -99.0 -99.0

510 23.3103693 30.8603881 0.149 1.476 0.112 1.256 0.679 0.919 1.936 1.08 1.321 0.352 8.289 0.738

511 23.5826128 30.816185 -99.0 -99.0 0.31 0.297 16.07 0.502 3.436 1.159 23.32 0.046 45.95 0.643

512 23.50917 30.8411049 0.77 1.973 0.49 1.56 1.65 0.91 7.34 1.051 3.89 0.0 5.11 0.429

513 23.3850146 31.0214745 0.042 0.811 0.035 0.832 0.178 0.505 0.48 0.663 0.23 0.001 -99.0 -99.0

514 23.59976 30.9504538 -99.0 -99.0 -99.0 -99.0 0.2 2.861 2.96 2.027 2.99 0.065 14.55 1.43

515 23.5390177 30.9218105 0.379 0.419 0.483 0.405 0.56 0.406 0.79 0.506 0.35 0.001 -99.0 -99.0

Star formation in M 33: Spitzer photometry of discrete sources